Faculty Bibliography

INTRODUCTION/BACKGROUND:During the COVID-19 pandemic, central venous access line teams were implemented at many hospitals throughout the world to provide access for critically ill patients. The objective of this study was to describe the structure, practice patterns and outcomes of these vascular access teams during the COVID-19 pandemic. METHODS:We conducted a cross sectional, self-reported study of central venous access line teams in hospitals afflicted with the COVID-19 pandemic. In order to participate in the study, hospitals were required to meet one of the following criteria: a) development of a formal plan for a central venous access line team during the pandemic, b) implementation of a central venous access line team during the pandemic, c) placement of central venous access by a designated practice group during the pandemic as part of routine clinical practice, or d) management of an iatrogenic complication related to central venous access in a patient with COVID-19. RESULTS:Participants from 60 hospitals in 13 countries contributed data to the study. Central venous line teams were most commonly composed of vascular surgery and general surgery attending physicians and trainees. Twenty sites had 2,657 lines placed by their central venous access line team or designated practice group. During that time, there were 11 (0.4%) iatrogenic complications associated with central venous access procedures performed by the line team or group at those 20 sites. Triple lumen catheters, Cordis® catheters and non-tunneled hemodialysis catheters were the most common types of central venous lines placed by the teams. Eight (14%) sites reported experience placing central venous lines in prone, ventilated patients with COVID-19. A dedicated line cart was used by 35 (59%) of hospitals. Less than 50% (24, 41%) of the participating sites reported managing thrombosed central lines in COVID-patients. Twenty-three of the sites managed 48 iatrogenic complications in patients with COVID-19 (including complications caused by providers outside of the line team or designated practice group). CONCLUSIONS:Implementation of a dedicated central venous access line team during a pandemic or other healthcare crisis is a way by which physicians trained in central venous access can contribute their expertise to a stressed healthcare system. A line team composed of physicians with vascular skill sets provides relief to resource-constrained ICU, ward, and emergency medicine teams with a low rate of iatrogenic complications relative to historical reports. We recommend that a plan for central venous access line team implementation be in place for future healthcare crises.

OBJECTIVE:The objective of this study was to evaluate the efficacy, durability, and safety of radiofrequency ablation (RFA) and endovenous laser ablation (EVLA) of the great saphenous vein (GSV) and small saphenous vein (SSV) to treat symptomatic venous reflux in patients receiving therapeutic anticoagulation. METHODS:tests, Fisher exact test, Kaplan-Meier curves, and Cox proportional hazard modeling. RESULTS:There were 100 procedures performed in 65 patients receiving anticoagulation and 127 procedures in 89 control patients. Mean follow-up time was 467 days. The most common indications for anticoagulation were atrial fibrillation (52%), remote DVT (29%), and mechanical heart valves (8%). Patients receiving anticoagulation were on average older (67 years vs 52 years), were more likely to be male (51% vs 27%), and had higher rates of coronary disease (9% vs 0%) and hypertension (55% vs 20%), although they were more likely to have never smoked (86% vs 69%). There were 127 RFA procedures (56%) and 100 EVLA procedures (44%); 189 procedures treated the GSV or its tributaries (83%), and 38 treated the SSV (17%). At 1 year, the target vessel remained ablated after 96% of procedures performed with anticoagulation and in 99% of controls; at 18 months, rates were 92% vs 95% (P = .96). Rates of persistent ablation did not differ significantly by vessel treated (P = .28), EVLA vs RFA (P = .36), or use of antiplatelet therapy (P = .92). One patient had bleeding from a phlebectomy site 2 days postprocedurally when supratherapeutic on warfarin; this was controlled with pressure. DVT in the ipsilateral leg occurred within 90 days after 1 of 100 (1%) procedures in patients receiving anticoagulation and 2 of 127 (1.6%) procedures in control patients; endothermal heat-induced thrombosis rates were similarly 1 of 100 (1%) procedures in patients receiving anticoagulation and 1 of 127 (0.8%) in control patients. CONCLUSIONS:This is the largest series to date reporting >30-day follow-up for patients undergoing venous ablation procedures while receiving anticoagulation and the longest follow-up reported of any series. Durability, safety, and efficacy of vein ablation in patients receiving anticoagulation are comparable to those in control patients. Anticoagulation should not be considered a contraindication to endothermal ablation of the GSV or SSV for symptomatic venous reflux.

OBJECTIVE:Ischemic complications (including in the lower extremity, visceral, spinal, and pelvic territories) following standard endovascular aortic repair (EVAR) are well recognized but fortunately uncommon. The incidence of such complications following fenestrated and branched aortic repair (F/BEVAR) has not been well defined in the literature. The objective of this study was to compare the incidence of ischemic complications between EVAR and F/BEVAR and to elucidate potential risk factors for these complications. METHODS:We identified all patients who underwent EVAR from 2003 to 2017 or F/BEVAR from 2012 to 2017 in the national Vascular Quality Initiative database. We assessed differences in perioperative ischemic outcomes with methods including logistic regression and inverse probability of treatment propensity score weighting, using a composite endpoint of lower extremity ischemia, intestinal ischemia, stroke, or new dialysis as the primary endpoint. RESULTS:The data comprised 35,379 EVAR patients and 3374 F/BEVAR patients. F/BEVAR patients were more likely to be female, have had previous aneurysm repairs, and be deemed unfit for open aneurysm repair; they were less likely to have ruptured aneurysms; and they had higher estimated blood losses, contrast volumes, and fluoroscopy and procedure times. The incidence of any ischemic event (7.7% vs 2.2%) as well as the incidences of the component endpoints of lower extremity ischemia (2.3% vs 1.0%), intestinal ischemia (2.7% vs 0.7%), stroke (1.5% vs 0.3%), and new hemodialysis (3.1% vs 0.4%) were all significantly increased (all P < .001) in F/BEVAR compared with standard EVAR. After propensity adjustment, F/BEVAR conferred increased odds of any ischemic complication (1.8), intestinal ischemia (2.0), lower extremity ischemia (1.3), new hemodialysis (10.2), and stroke (2.3). CONCLUSIONS:Rates of lower extremity ischemia, intestinal ischemia, new dialysis, and stroke each range from 0% to 1% for standard EVAR and 1% to 3% for F/BEVAR. The incidence of perioperative ischemic complications following F/BEVAR is significantly increased compared to EVAR. The real-world data in this study should help guide decision-making for surgeons and patients as well as serve as one metric for progress in device and technique development. Improvements in ischemic complications may come from continued technology development such as smaller sheaths, improved imaging to decrease procedure time and contrast volume, embolic protection, and increased operator skill with wire and catheter manipulation.

PURPOSE/OBJECTIVE:To describe our clinical experience in using a system with a 4 Fr catheter profile for endovascular creation of arteriovenous fistulae (AVF) in hemodialysis patients. METHODS:This was a multi-operator, single center, single-arm, prospective study intended to evaluate safety and efficacy of a 4 Fr endovascular AVF (endoAVF) system for the creation of vascular access in hemodialysis patients. The study was performed after institutional review board approval at Italian Hospital (Asuncion, Paraguay). Patients were followed at regular intervals through 6 months to determine procedural, maturation, and cannulation success as well as intervention rate and patency. RESULTS:From May to November 2016, 32 patients underwent the endoAVF procedure with no device-related adverse events. An endoAVF was successfully created in the proximal forearm for all 32 patients (20 between the radial artery and radial vein; 12 between the ulnar artery and ulnar vein). Wrist access was used for 72% (23/32) of the procedures for the arterial catheter and 59% (19/32) of the procedures for the venous catheter. The device successfully created an endoAVF in every patient for a technical success rate of 100% (32/32). The device- or procedure-related serious adverse event rate was 3% (1/32); one patient experienced a venous guidewire perforation successfully managed with a stent graft. Primary and cumulative patency rates through 6 months were 83% and 87%, respectively, with an intervention rate of 0.21 per patient-year. Physiological suitability, as defined by target flow rates ≥500 ml/min and cannulation vessel diameters ≥4 mm, were achieved in 91% (29/32) of patients by 90 days. Successful 2-needle cannulation was achieved in 78% (21/27) by 90 days, with mean time to cannulation of 43 ± 14 days. Functional cannulation, as defined by successful 2-needle cannulation for two-thirds of the dialysis sessions within 1 month, was achieved in 95% (20/21) of the patients that were successfully cannulated for an overall rate of 74% (20/27). All patients that achieved functional cannulation had their central venous catheters (CVCs) removed before the 90-day follow up for a CVC removal rate of 74% (20/27). CONCLUSIONS:The 4 Fr endoAVF system allowed for multiple access and fistula creation site options to tailor the procedure to individual patient anatomy. Further, the outcomes are comparable to previous generation endoAVF technology, with a potentially improved safety profile due to the use of arteries at the wrist for access.

OBJECTIVES/OBJECTIVE:Our aims were to examine the prevalence and genetic predictors of aspirin and clopidogrel high on-treatment platelet reactivity (HoTPR), and associated adverse cardiovascular outcomes in patients with peripheral arterial disease (PAD). BACKGROUND:The association of aspirin and clopidogrel HoTPR with outcomes in PAD remains unclear. METHODS:This is a prospective cohort study of patients with angiographically documented PAD involving carotid and lower extremity arteries. Aspirin and clopidogrel HoTPR (using the VerifyNow Assay) and associated genetic predictors were compared to clinical outcomes. The primary end-point was a composite of major adverse cardiovascular events: all-cause mortality, myocardial infarction, stroke, target vessel revascularization (TVR) and limb-loss in patients who underwent extremity intervention. RESULTS:The study was stopped prematurely due to slow patient enrolment. Of 195 patients enrolled, the primary analysis was performed in 154 patients taking both drugs. Aspirin HoTPR was present in 31 (20%) and clopidogrel HoTPR in 76 (49%) patients. There was a trend toward more primary composite outcome events with PRU ≥ 235 (52% freedom-from-event rate vs. 70% for PRU < 235; P = 0.09). TVR was higher in those with PRU ≥ 235 (20 vs. 6%, unadjusted P = 0.02). There was no association between aspirin HoTPR and combined outcomes. Single nucleotide polymorphisms in serum paraoxonase/arylesterase 1 (PON1) gene was associated with aspirin HoTPR (P = 0.005) while SNP in phospholipase A2, group III (PLA2G3) gene was associated with clopidogrel HoTPR (P = 0.002). CONCLUSION/CONCLUSIONS:Clopidogrel HoTPR was significantly associated with TVR, while aspirin HoTPR was not associated with adverse clinical outcomes in patients with PAD.

BACKGROUND: Scalp sensation and pain comprise the most common side effect of transcranial magnetic stimulation (TMS), which can reduce tolerability and complicate experimental blinding. OBJECTIVE: We explored whether changing the width of single TMS pulses affects the quality and tolerability of the resultant somatic sensation. METHODS: Using a controllable pulse parameter TMS device with a figure-8 coil, single monophasic magnetic pulses inducing electric field with initial phase width of 30, 60, and 120 micros were delivered in 23 healthy volunteers. Resting motor threshold of the right first dorsal interosseus was determined for each pulse width, as reported previously. Subsequently, pulses were delivered over the left dorsolateral prefrontal cortex at each of the three pulse widths at two amplitudes (100% and 120% of the pulse-width-specific motor threshold), with 20 repetitions per condition delivered in random order. After each pulse, subjects rated 0-to-10 visual analog scales for Discomfort, Sharpness, and Strength of the sensation. RESULTS: Briefer TMS pulses with amplitude normalized to the motor threshold were perceived as slightly more uncomfortable than longer pulses (with an average 0.89 point increase on the Discomfort scale for pulse width of 30 micros compared to 120 micros). The sensation of the briefer pulses was felt to be substantially sharper (2.95 points increase for 30 micros compared to 120 micros pulse width), but not stronger than longer pulses. As expected, higher amplitude pulses increased the perceived discomfort and strength, and, to a lesser degree the perceived sharpness. CONCLUSIONS: Our findings contradict a previously published hypothesis that briefer TMS pulses are more tolerable. We discovered that the opposite is true, which merits further study as a means of enhancing tolerability in the context of repetitive TMS.

Endovascular stent grafting (EVAR) is now the preferred approach to repair of abdominal aortic aneurysms for many patients. One of the most common complications associated with EVAR is the development of an endoleak, or continued flow of blood into the aneurysm sac outside the graft. Type II endoleaks, those due to retrograde flow through a branch vessel such as the inferior mesenteric artery (IMA) or a lumbar artery, are the most common. Options for treatment include transarterial embolization, translumbar embolization, and laparoscopic ligation. Embolization techniques require reintervention in approximately 20%, with less than half free from aneurysm sac growth at five years, though current evidence is insufficient to determine a clear threshold for intervention or optimal technique.[1,2]

OBJECTIVE/BACKGROUND: Aorto-bifemoral bypass remains the gold standard for treatment of aortoiliac occlusive disease (AIOD) in patients with advanced (TASC D) lesions, but has significant associated morbidity and mortality. Treatment with a unibody stent-graft positioned at the aortic bifurcation is a potential endovascular option for the treatment of AIOD. The current study examines the safety, efficacy, and early patency rates of the Endologix AFX unibody stent-graft for treatment of AIOD. METHODS: A multicenter retrospective review was conducted of patients treated exclusively for AIOD with the AFX device. Primary, assisted primary, and secondary patency rates were noted. Clinical improvement was assessed using Rutherford classification and ankle brachial index. Mean duration of follow-up was 22.2 +/- 11.2 months. Ninety-one patients (56 males [62%]) were studied. RESULTS: Sixty-seven patients (74%) presented with lifestyle-limiting intermittent claudication and the remaining 24 (26%) had critical limb ischemia. Technical success was 100%. Complications included groin infection (n = 4 [4%]), groin hematoma (n = 4 [4%]), common iliac rupture (n = 4 [4%]), iliac dissection (n = 4 [4%]), and thromboembolic event (n = 3 [3%]; one femoral, one internal iliac artery, and one internal iliac with bilateral popliteal/tibial thromboemboli). Thirty-day mortality was 1% (1/91) resulting from a case of extensive pelvic thromboembolism. At 1 year, 73% of patients experienced improvement in Rutherford stage of -3 or greater compared with baseline. Nine patients (10%) required 16 secondary interventions. At all time points, primary patency rates were > 90%, assisted patency rates were > 98%, and secondary patency rates were 100%. CONCLUSION: This is the largest study to examine the use of the Endologix AFX unibody stent-graft for the treatment of AIOD. Use of the AFX stent-graft appears to be a safe and effective endovascular treatment for complex AIOD.