Faculty Bibliography

OBJECTIVES/OBJECTIVE:The pandemic of Coronavirus disease 2019 (COVID-19) has caused devastating morbidity and mortality worldwide. In particular, thromboembolic complications have emerged as a key threat in COVID-19. We assessed our experience with deep venous thrombosis (DVT) in patients with COVID-19. METHODS:We performed a retrospective analysis of all patients with COVID-19 undergoing upper or lower extremity venous duplex ultrasonography at an academic health system in New York City between March 3 2020 and April 12 2020 with follow-up through May 12 2020. A cohort of hospitalized patients without COVID-19 (non-COVID-19) undergoing venous duplex ultrasonography from December 1 2019 to December 31 2019 was used for comparison. The primary outcome was DVT. Secondary outcomes included pulmonary embolism (PE), in-hospital mortality, admission to intensive care unit, and antithrombotic therapy. Multivariable logistic regression was performed to identify risk factors for DVT and mortality. RESULTS:Of 443 patients (188 COVID-19 and 255 non-COVID-19) undergoing venous duplex ultrasonography, patients with COVID-19 had higher incidence of DVT (31% vs. 19%; P=0.005), compared to the non-COVID-19 cohort. The incidence of PE was not statistically different between the COVID-19 and non-COVID-19 cohorts (8% vs. 4%; P=.105). The DVTs in the COVID-19 group were more distal (63% vs. 29%; P<.001) and bilateral (15% vs. 4%; P<.001). The result of duplex ultrasonography had a significant impact on the antithrombotic plan; 42 (72%) patients with COVID-19 in the DVT group had their therapies escalated while 49 (38%) and 3 (2%) patients had their therapies escalated and de-escalated in the non-DVT group, respectively (P<.001). Within the COVID-19 cohort, the D-dimer was significantly higher in the DVT group at the time of admission (2,746 ng/mL vs 1,481 ng/mL; P=.004) and at the time of the duplex exam (6,068 ng/mL vs. 3,049 ng/mL; P<0.01). At multivariable analysis, male sex (odd ratio (OR) 2.27; 95% confidence interval (CI), 1.06-4.87; P=.035), ICU admission (OR 3.42; 95% CI, 1.02-11.44; P=.046) and extracorporeal membrane oxygenation (OR 5.5; 95% CI, 1.01-30.13; P=.049) were independently associated with DVT. CONCLUSION/CONCLUSIONS:Given the high incidence of venous thromboembolic events in this population, we support the decision to empirically initiate therapeutic anticoagulation in patients with low bleeding risk and severe COVID-19 infection, with duplex ultrasonography reserved for patients with high clinical suspicion of VTE in which anticoagulation may pose a life-threatening consequence. Further study is warranted in patients with COVID-19 to elucidate the etiology of vascular thromboembolic events and guide prophylactic and therapeutic interventions in these patients.

The American Venous Forum (AVF) and the Society for Vascular Surgery set forth these guidelines for the management of endothermal heat-induced thrombosis (EHIT). The guidelines serve to compile the body of literature on EHIT and to put forth evidence-based recommendations. The guidelines are divided into the following categories: classification of EHIT, risk factors and prevention, and treatment of EHIT. One major feature is to standardize the reporting under one classification system. The Kabnick and Lawrence classification systems are now combined into the AVF EHIT classification system. The novel classification system affords standardization in reporting but also allows continued combined evaluation with the current body of literature. Recommendations codify the use of duplex ultrasound for the diagnosis of EHIT. Risk factor assessments and methods of prevention including mechanical prophylaxis, chemical prophylaxis, and ablation distance are discussed. Treatment guidelines are tailored to the AVF EHIT class (ie, I, II, III, IV). Reference is made to the use of surveillance, antiplatelet therapy, and anticoagulants as deemed indicated, and the recommendations incorporate the use of the novel direct oral anticoagulants. Last, EHIT management as it relates to the great and small saphenous veins is discussed.

OBJECTIVE:Wound complications after major lower extremity amputations are a cause of significant morbidity in vascular surgery patients. Recent publications have demonstrated the efficacy of the closed incision negative pressure dressing at preventing surgical site infections (SSIs); however, there are limited data on its use in major lower extremity amputations. This study sought to assess if closed incision negative pressure wound therapy (NPWT) would reduce the risk of complications as compared to a standard dressing in patients with peripheral vascular disease undergoing major lower extremity amputation. METHODS:system (Acelity L.P. Inc., San Antonio, TX, USA) was applied intraoperatively at the discretion of the operating surgeon and removed 5 to 7 days postoperatively. The standard group received a non-adherent dressing with an overlying compression dressing. Amputation incisions were assessed and wound complications were recorded. Student's t-test and two-sample proportion z-test were used for statistical analysis. A P value < .05 was considered statistically significant. RESULTS:For comorbidities, there was a higher incidence of tobacco use in the NPWT as compared to the standard group (44% vs. 13%; P = .011), as well as trends towards increased prior amputations, anemia, hyperlipidemia, and chronic obstructive pulmonary disorder in the NPWT group. For risk factors, there were more dirty wounds in the NPWT as compared to the standard group (52% vs. 26%; P = .046). For outcomes, there were fewer wound complications in the NPWT as compared to the standard group (13% vs. 39%; P = .037). The types of wound-related complications in the NPWT group included one wound dehiscence with a deep SSI, one superficial SSI and one incision line necrosis. In the standard group, there were 4 wound dehiscences with deep SSI, 3 superficial SSIs, 4 incision line necroses and 1 stump hematoma. The rates of perioperative mortality and amputation revision did not differ significantly between the NPWT and the standard group (3% vs. 4% and 4.3% vs. 10%, respectively). CONCLUSIONS:Closed incision negative pressure wound therapy may decrease the incidence of wound complications in vascular patients undergoing major lower extremity amputation. This held true even amongst a population that was potentially at higher risk. This therapy may be considered for use in lower extremity major amputations.

Objective: Aortic neck dilation (AND) can occur in nearly 25% of patients after EVAR, resulting in loss of proximal seal and aortic rupture. Fenestrated endovascular aneurysm repair (FEVAR) affords increased treatment options for patients with shorter infrarenal aortic necks; however, AND has not been well characterized in these patients. This study sought to compare AND in patients undergoing FEVAR vs standard endovascular aneurysm repair (EVAR).
Method(s): Retrospective review was conducted of prospectively collected data of 20 consecutive FEVAR patients (Cook Zenith fenestrated; Cook Medical, Bloomington, Ind) and 20 EVAR patients (Cook Zenith). Demographic and anatomic characteristics, procedural details, and clinical outcome were analyzed. Preoperative, 1-month postoperative, and longest follow-up computed tomography scans were analyzed using a dedicated three-dimensional workstation. Abdominal aortic aneurysm (AAA) neck diameter was measured in 5-mm increments from the lowest renal artery. Standard statistical analysis was performed.
Result(s): Demographic characteristics did not differ significantly between the two cohorts. The FEVAR group had larger mean aortic diameter at the lowest renal artery, shorter infrarenal aortic neck length, increased prevalence of nonparallel neck shape, and longer AAA length (Table). On follow-up imaging, the suprarenal aortic segment dilated significantly more at all suprarenal locations in the FEVAR cohort, whereas the infrarenal aortic neck segment dilated significantly less compared with the EVAR group (Table). The FEVAR group demonstrated significantly greater sac regression vs the EVAR group. Positive aortic remodeling, as evidenced by increased distance from the celiac axis to the most cephalad margin of the AAA, occurred to a more significant degree in the FEVAR cohort. Device migration, endoleak occurrence, and need for reintervention were similar in both groups.
Conclusion(s): Compared with EVAR, patients undergoing FEVAR had greater extent of suprarenal AND, consistent with a more diseased native proximal aorta. However, the infrarenal neck, which is shorter and also more diseased in FEVAR patients, appears more stable in the postoperative period compared with EVAR cases. Moreover, the FEVAR cohort had significantly greater sac shrinkage and improved aortic remodeling. The suprarenal seal zone in FEVAR may confer a previously undescribed increased level of protection against infrarenal neck dilation and lessen endotension, resulting in more rapid and dramatic sac shrinkage and contributing to a more durable aortic repair. [Formula presented]
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Objective: Whereas clopidogrel is effective at decreasing cardiovascular events in patients with peripheral artery disease, a substantial number of events continue to occur. This study investigated the variability in response to clopidogrel and its relationship with clinical outcomes.
Method(s): There were 300 patients enrolled in the Platelet Activity in Vascular Surgery and Cardiovascular Events (PACE) study before lower extremity revascularization, of whom 119 were receiving clopidogrel. Platelet aggregation was measured in response to adenosine diphosphate (ADP) 2M immediately before revascularization. Patients were observed longitudinally for a median follow-up of 18 months. The primary end point was major adverse limb events (MALEs), defined by major amputation or reoperation of the affected limb. Patients were stratified into groups according to the percentage ADP-induced aggregation at 300 seconds (<50% aggregation, normal responder; >=50% aggregation, poor responder).
Result(s): Overall, the median age was 70 years (62-76 years), and 39.5% were female. Thirty-six (30.3%) patients had a MALE event (15 major amputation and 25 major reoperation); 60 patients underwent open or hybrid operations, and 50 patients underwent endovascular procedures. The remaining nine patients had no interventions. Of the group of 119 patients, 97 patients were taking aspirin. Overall, median aggregation to ADP 2M was 22.5% (Q1-Q3, 10%-50%), and 27 patients (26%) were clopidogrel nonresponders. Baseline aggregation was higher in patients who went on to develop a MALE than in those without a MALE (43% vs 20%; P =.018). Patients with aggregation > median (22.5%) were more likely to experience a MALE than were patients with aggregation < median (69% vs 31%; hazard ratio [HR], 2.71; 95% confidence interval [CI], 1.23-5.98; P =.013). After multivariable adjustment for age, sex, race/ethnicity, body mass index, diabetes, coronary artery disease, and aspirin, aggregation > median was associated with MALEs (adjusted HR, 2.67; 95% CI, 1.18-6.01; P =.018). When stratified by established cutoffs for responsiveness to clopidogrel (50% aggregation), 27 (26%) patients were poor responders. Poor responders were more likely to experience MALEs than normal responders (59% vs 41%; HR, 2.33; 95% CI, 1.11-4.89; P =.026). After multivariable adjustment, poor responder status trended toward an increased risk of MALE compared with a normal responder (adjusted HR, 2.18; 95% CI, 1.00-4.78; P =.051).
Conclusion(s): Among patients undergoing lower extremity revascularization, poor response to clopidogrel is associated with increased risk for major adverse limb events. Preoperative screening to ensure therapeutic clopidogrel response should be considered in these patients.
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The American Venous Forum (AVF) and the Society for Vascular Surgery set forth these guidelines for the management of endothermal heat-induced thrombosis (EHIT). The guidelines serve to compile the body of literature on EHIT and to put forth evidence-based recommendations. The guidelines are divided into the following categories: classification of EHIT, risk factors and prevention, and treatment of EHIT.One major feature is to standardize the reporting under one classification system. The Kabnick and Lawrence classification systems are now combined into the AVF EHIT classification system. The novel classification system affords standardization in reporting but also allows continued combined evaluation with the current body of literature. Recommendations codify the use of duplex ultrasound for the diagnosis of EHIT. Risk factor assessments and methods of prevention including mechanical prophylaxis, chemical prophylaxis, and ablation distance are discussed.Treatment guidelines are tailored to the AVF EHIT class (ie, I, II, III, IV). Reference is made to the use of surveillance, antiplatelet therapy, and anticoagulants as deemed indicated, and the recommendations incorporate the use of the novel direct oral anticoagulants. Last, EHIT management as it relates to the great and small saphenous veins is discussed.

OBJECTIVE/UNASSIGNED:Patients who present acutely with a femoral deep vein thrombosis (DVT) diagnosed by ultrasound are often treated with anticoagulation and instructed to follow-up electively. This study sought to assess whether obtaining axial imaging of the central venous system results in the identification of additional iliocaval pathology warranting treatment. METHODS/UNASSIGNED:This study was a retrospective review of a prospectively maintained registry from November 2014 through April 2017 with follow-up through March 2020. Consecutive patients with a diagnosis of femoral DVT diagnosed by ultrasound were evaluated; those who underwent axial imaging of the iliocaval system (Group A) were compared to those who did not undergo imaging of the central veins (Group B). The primary outcome was the performance of any percutaneous central venous intervention. Secondary outcomes included the extent of DVT identified on duplex and after axial imaging, follow-up duplex patency and persistence of severe symptoms. RESULTS/UNASSIGNED:Eighty patients presented with an ultrasound diagnosis of a femoral vein DVT. Mean follow-up was 551 ± 502 days. Group A comprised 24 patients (30%) and Group B comprised 56 patients (70%). Baseline demographics did not differ significantly between the 2 groups. After duplex imaging, Group A exhibited an increased prevalence of DVT in the common femoral vein. After central imaging, Group A exhibited an increased prevalence of DVT in the iliocaval veins. The number of patients who underwent invasive treatment differed significantly between the 2 groups, Group A 16/24 (67%) vs. Group B 9/56 (16%), P < 0.0001. The number of patients that demonstrated duplex patency and had persistent symptoms on follow-up did not differ significantly. CONCLUSIONS/UNASSIGNED:Patients with an ultrasound diagnosis of femoral DVT may have additional iliocaval pathology warranting intervention. Well-selected imaging of the central veins may reveal a more complete picture, potentially altering management.

The novel coronavirus 2019 (SARS-CoV-2) was first identified in January 2020 and has since evolved into a pandemic affecting >200 countries. The severity of presentation is variable and carries a mortality between 1% and 3%. We continue to learn about the virus and the resulting acute respiratory illness and hypercoagulability; however, much remains unknown. In our early experience in a high-volume center, we report a series of four cases of acute peripheral artery ischemia in patients with COVID-19 in the setting of elevated D-dimer levels.

OBJECTIVE:To provide an evidence-based overview of endovenous laser ablation and describe its role as an effective and durable technique for the management of superficial venous insufficiency. METHODS:The published literature on the treatment of varicose veins using endovenous laser ablation was reviewed. The literature search focused on the history of endovenous laser ablation, its safety and durability, known complications, and differences in outcomes based on the iterations of fiber type and laser wavelength. RESULTS:Treatment safety and efficacy of endovenous laser ablation appear to be based on the amount of energy administered over a defined distance, or the linear endovenous energy density. The ideal linear endovenous energy density varies with the laser wavelength and fiber-type. Post-operative pain and bruising may be reduced by the use of higher wavelength fibers or the use of radial or jacket-tip fibers as compared to bare-tip fibers. The incidence of endothermal heat-induced thrombosis remains low and has declined with increasing experience. Reports have demonstrated a greater than 90% technical success rate with saphenous endovenous laser ablation, long-term durability of ablation, and commensurate improvement in quality of life. CONCLUSIONS:Endovenous laser ablation is a safe and durable treatment option for the management of incompetent superficial and perforator veins of the lower extremities. As an endothermal technology, it remains a key component of the standard of care for the treatment of chronic venous insufficiency.