Faculty Bibliography

Purpose: Mechanical thrombectomy for the treatment of deep vein thrombosis (DVT) is being increasingly utilized to reduce symptoms and prevent postthrombotic syndrome (PTS), but more data on clinical outcomes are needed. Mechanical thrombectomy was studied in the ClotTriever Outcomes (CLOUT) registry with 6-month full analysis outcomes reported herein. Materials and Methods: The CLOUT registry is a prospective, all-comer study that enrolled 500 lower extremity DVT patients across 43 US sites treated with mechanical thrombectomy using the ClotTriever System. Core-lab assessed Marder scores and physician-assessed venous patency by duplex ultrasound, PTS assessment using Villalta score, venous symptom severity, pain, and quality of life scores through 6 months were analyzed. Adverse events were identified and independently adjudicated. Results: All-cause mortality at 30 days was 0.9%, and 8.6% of subjects experienced a serious adverse event (SAE) within the first 30 days, 1 of which (0.2%) was device related. SAE rethrombosis/residual thrombus incidence was 4.8% at 30 days and 8.0% at 6 months. Between baseline and 6 months, venous flow increased from 27.2% to 92.5% of limbs (P < 0.0001), and venous compressibility improved from 28.0% to 91.8% (P < 0.0001), while median Villalta scores improved from 9.0 at baseline to 1.0 at 6 months (P < 0.0001). Significant improvements in venous symptom severity, pain, and quality of life were also demonstrated. Outcomes from iliofemoral and isolated femoral-popliteal segments showed similar improvements. Conclusion: Outcomes from the CLOUT study, a large prospective registry for DVT, indicate that mechanical thrombectomy is safe and demonstrates significant improvement in symptoms and health status through 6 months. Level of Evidence 3: Non-randomized controlled cohort/follow-up study.

OBJECTIVE:Studies assessing the effect of anticoagulants on endovenous thermal ablation (ETA) are limited to patients on warfarin. As such, the aim of this study was to assess the efficacy and safety of ETA in patients taking direct oral anticoagulants (DOACs). We hypothesized that the outcome of ETA in patients taking DOAC is not superior to the outcome in patients taking DOAC. METHODS:A retrospective review was performed to identify patients undergoing radiofrequency ablation (RFA) and endovenous laser ablation (EVLA) with 1470 nm diode laser fibers for symptomatic great or small saphenous venous reflux from 2018 to 2020. Patients were dichotomized into those receiving therapeutic dose of DOACs peri-procedurally and those not receiving anticoagulants (control). Outcomes of interest included the rates of treated vein closure at 7-days and 9-months, deep venous thrombosis (DVT), endothermal heat-induced thrombosis (EHIT) and bleeding peri-procedurally. RESULTS:There were 87 procedures performed in 69 patients receiving DOACs and 295 procedures in 232 control patients. Patients receiving DOACs were more often older (mean, 65 years vs 55 years; P<.001) and male (70% vs 37%; P<.001), with higher prevalence of venous thromboembolism and more severe CEAP classification (5 or 6), compared to control patients. Those receiving DOAC were more likely to have history of DVT (44% vs 6%; P<.001), PE (13% vs 0%; P<.001) and phlebitis (32% vs 15%; P<.001). Procedurally, RFA was used more frequently in the control group (92% vs 84%; P=.029), with longer segments of vein treated (mean 38 mm vs 35 mm, respectively; P=.028). No major or minor bleeding events nor any EHITs occurred in either group. Two patients (0.7%) in the control group developed DVT whereas no DVT was observed in the those receiving DOAC (P=.441). At 9-months, the treated vein remained ablated after 94.4% of procedures performed in patients receiving DOACs and 98.4% of controls (P=.163). On multivariable analysis, DOAC was not associated with an increased risk of vein recanalization (hazard ratio, 5.76; 95% confidence interval, 0.57-58.64; P=.139). An increased pre-procedural vein diameter and EVLA were associated with an increased risk of recanalization. CONCLUSION/CONCLUSIONS:In this study of patients undergoing ETA for symptomatic saphenous venous reflux, peri-procedural use of DOAC did not adversely affect the efficacy of endovenous ablation to at least 9-months. Furthermore, it did not confer additional risk of bleeding, DVT and EHIT peri-procedurally. As such, the early outcome of ETA in patients not taking DOAC may not be superior to the outcome in patients taking DOAC.

Abdominal aortic aneurysms (AAA) is a multifactorial complex disease with life-threatening consequences. While Genome-wide association studies (GWAS) have revealed several single nucleotide polymorphisms (SNPs) located in the genome of individuals with AAA, the link between SNPs with the associated pathological signals, the influence of risk factors on their distribution and their combined analysis is not fully understood. We integrated 86 AAA SNPs from GWAS and clinical cohorts from the literature to determine their phenotypical vulnerabilities and association with AAA risk factors. The SNPs were annotated using snpXplorer AnnotateMe tool to identify their chromosomal position, minor allele frequency, CADD (Combined Annotation Dependent Depletion), annotation-based pathogenicity score, variant consequence, and their associated gene. Gene enrichment analysis was performed using Gene Ontology and clustered using REVIGO. The plug-in GeneMANIA in Cytoscape was applied to identify network integration with associated genes and functions. 15 SNPs affecting 20 genes with a CADD score above ten were identified. AAA SNPs were predominantly located on chromosome 3 and 9. Stop-gained rs5516 SNP obtained high frequency in AAA and associated with proinflammatory and vascular remodeling phenotypes. SNPs presence positively correlated with hypertension, dyslipidemia and smoking history. GO showed that AAA SNPs and their associated genes could regulate lipid metabolism, extracellular matrix organization, smooth muscle cell proliferation, and oxidative stress, suggesting that part of these AAA traits could stem from genetic abnormalities. We show a library of inborn SNPs and associated genes that manifest in AAA. We uncover their pathological signaling trajectories that likely fuel AAA development.

OBJECTIVE:Beta-blockers are first-line anti-impulse therapy in patients presenting with acute type B aortic dissection (TBAD). However, little is understood about their impact after aortic repair. The aim of this study was to evaluate the role of postoperative beta-blocker use on outcomes of thoracic endovascular aortic repair (TEVAR) in TBAD. METHODS:The Vascular Quality Initiative database was queried for all patients undergoing TEVAR for TBAD from 2012 to 2020. Aortic-related reintervention, all-cause mortality and effect of TEVAR on false lumen thrombosis of the treated aortic segment were assessed and compared between patients treated with and without beta-blocker postoperatively. Cox proportional hazards models were used to estimate the effect of beta-blocker therapies on outcomes. RESULTS:1,114 patients undergoing TEVAR for TBAD were identified with a mean follow-up of 18±12 months. The mean age was 61.1±11.9 years, and 791 (71%) were male. 935 (84%) patients were maintained on beta-blocker at discharge and follow-up. Patients on beta-blocker were more likely to have an entry tear originating in zones 1-2 (22% vs 13%; P=.022). The prevalence of acute, elective and symptomatic AD, concurrent aneurysm, number of endografts used, distribution of the proximal and distal zones of dissection and operative time were comparable between the two cohorts. At 18-months, significantly more complete false lumen thrombosis (58 vs 47%; log-rank P=.018) was observed in patients on beta-blocker while the rates of aortic-related reinterventions (13% vs 9%; log-rank P=.396) and mortality (0.2% vs 0.7%; log-rank P=.401) were similar in patients with and without beta-blocker, respectively. Even after adjusting for clinical and anatomic factors, postoperative beta-blocker use was associated with increased complete false lumen thrombosis (HR 1.56; 95% CI: 1.10-2.21; P=.012) but did not affect mortality or aortic-related reintervention. A secondary analysis of beta-blocker use in acute versus chronic TBAD showed a higher rate of complete false lumen thrombosis in patients on beta-blocker in chronic TBAD (59% vs 38%; log-rank P=.038). In contrast, there was no difference in the rate of complete false lumen thrombosis in acute TBAD between the two cohorts (58% vs 51%; log-rank P=.158). When analyzed separately, postoperative ACE inhibitor use did not affect the rates of complete false lumen thrombosis, mortality and aortic-related reintervention. CONCLUSIONS:Beta-blocker use was associated with promotion of complete false lumen in patients undergoing TEVAR for TBAD. In addition to its role in acute setting, anti-impulse control with beta-blocker appears to confer favorable aortic remodeling and may improve outcomes after TEVAR, particularly for chronic TBAD.

OBJECTIVE:Current guidelines recommend dual antiplatelet therapy (DAPT) in patients undergoing carotid artery stenting. The most common DAPT regimen is aspirin and clopidogrel, a P2Y12 receptor antagonist; however, the prevalence of clopidogrel resistance (CR) in patients undergoing percutaneous coronary interventions may exceed 60%. Few studies have investigated the prevalence and impact of CR in patients undergoing extracranial carotid artery stenting, particularly transcarotid artery revascularization (TCAR). METHODS:Consecutive high-risk patients ≥ 18 years who underwent TCAR for high grade (≥70%) and/or symptomatic (≥50%) carotid stenosis with preoperative P2Y12 testing between August 2019 and December 2021 were identified across five institutions. Preoperative platelet reactivity was measured with the VerifyNow P2Y12 Reaction Unit (PRU) Test (Instrumentation Laboratory, Bedford, MA), with CR defined as PRU ≥ 194 and hyper-response as PRU <70. Patients without preoperative P2Y12 testing within 30 days prior to TCAR or those on a non-clopidogrel P2Y12 inhibitor preoperatively were excluded. The primary outcome of interest was prevalence of CR. Secondary outcomes of interest included the incidence of ischemic and hemorrhagic complications. RESULTS:= 1) between clopidogrel phenotypes. Three (3.3%) patients, one CR (PRU 240) and two responders (PRU 119 and PRU 189), experienced postoperative access site hematomas that required no subsequent intervention. No other index hospitalization hemorrhagic complications occurred. CONCLUSIONS:Using preoperative P2Y12 testing with a threshold PRU ≥ 194 to define CR, we identified a high prevalence of CR in patients undergoing TCAR similar to that in the pre-existing coronary literature. We found no significant differences in postoperative ischemic or hemorrhagic complications by clopidogrel response phenotype, although complication rates in the overall study cohort were low. CR may be a spectrum from responder to partial responder to complete non-responder, and this may account for the differences in our CR cohort compared to the ROADSTER 2 protocol deviation cohort. Further investigation is warranted to determine if a quantitative assessment of CR is sufficient to identify patients at risk of developing secondary cerebrovascular ischemic events in this patient population.

OBJECTIVE:Transplant renal artery stenosis (TRAS) after renal transplantation is a common cause of graft dysfunction and failure. Endovascular intervention in the form of percutaneous transluminal angioplasty (PTA) and stenting has rapidly become the dominant treatment modality for the TRAS. There is a paucity of clinical data on use of drug-eluting stent (DES) for TRAS. We investigated the outcomes of patients with clinically significant TRAS undergoing DES placement. METHODS:A retrospective review of patients with clinically significant TRAS undergoing PTA with DES placement from June 2014 to April 2021 was conducted. Patients treated for TRAS exhibited uncontrolled hypertension and/or unexplained allograft dysfunction. Patient demographics, procedural details, and follow-up outcomes were collected. Primary endpoints were the in-stent primary patency and graft survival. Secondary endpoints were freedom from reintervention, primary-assisted patency and access-related complications. RESULTS:Thirteen TRAS in twelve patients with graft function alteration were treated with DES. The median age was 57 years (interquartile range (IQR), 48-63 years), and nine (70%) patients were male (Table). The median follow-up was 9 months (IQR, 4-52 months). The most common comorbidity was hypertension (100%), coronary artery disease (83%) and diabetes. The median time from deceased donor transplant to intervention was 5.8 months (IQR, 3.5-6.7 months). TRAS was most commonly found at the juxta-ostial segment (77%). The procedure was performed with carbon dioxide angiography with minimal amount of iodinated contrast (median, 3 mL) under local anesthesia in nine (69%) and general anesthesia in four (31%) patients. The median stent diameter was 4.5 mm (IQR, 4-5 mm), and the median stent length was 15 mm (IQR, 15-18 mm). No intraoperative complications occurred. The rates of stenosis-free primary patency of the DES and graft survival were 76% and 100%, respectively. All three reinterventions for restenosis resulted from the kinking of the transplant renal artery proximal to the DES, which were treated by extending the stent more proximally 1-2 mm into the external iliac artery. There were no access-related complications. The median time to reintervention was 0.9 months (range, 0.23-2 months). Freedom from reintervention and primary-assisted patency were 76% and 100%, respectively. CONCLUSIONS:Our study demonstrates that DES is a safe and effective treatment modality in patients with TRAS at short to mid-term follow-up. As all reinterventions after DES were performed due to kinking of the transplant renal artery proximal to the stent, bridging of the DES 1-2 mm into the external iliac artery is recommended.

BACKGROUND:Potential complications of pelvic flow disruption during aortic aneurysm repair include buttock ischemia and mesenteric ischemia. Unilateral or bilateral hypogastric artery flow interruption, either from atherosclerosis or intentionally to facilitate aneurysm repair, is considered problematic in endovascular repair; however, it has not been well studied in open abdominal aortic aneurysm (AAA) repair (OAR). We sought to examine the effect of interruption of flow to one or both hypogastric arteries on outcomes after OAR. METHODS:The Society for Vascular Surgery Quality Initiative database was queried for all patients undergoing elective open AAA repair between 2003 and 2020. (redundant) Patients with appropriate data on their hypogastric arteries postoperatively were stratified into two groups-patent bilaterally (normal pelvic perfusion, NPP) and unilateral or bilateral occlusion or ligation (compromised pelvic perfusion, CPP). Primary endpoints were 30-day major morbidity (myocardial infarction, respiratory complications, renal injury, and lower extremity or intestinal ischemia) and mortality. RESULTS:During the study period, 9.492 patients underwent elective open AAA repair-860 (9.1%) with compromised pelvic perfusion and 8,632 (90.9%) with patent bilateral hypogastric arteries. The groups had similar cardiac risk factors, including a history of coronary artery disease, prior coronary intervention, and the use of P2Y12 inhibitors and statins. A majority of patients in the CPP cohort had concurrent iliac aneurysms (63.3% vs. 24.8%; P < 0.001). The perioperative mortality was significantly higher in patients with compromised pelvic perfusion (5.5% vs. 3.1%; P < 0.001). Bilateral flow interruption had a trend toward higher perioperative mortality compared to unilateral interruption (7.1% vs. 4.7%; P < 0.147). The CPP group also had increased rates of myocardial injury (6.7% vs. 4.7%; P = 0.012), renal complications (18.9% vs. 15.9%; P = 0.024), leg and bowel ischemia (3.5% vs. 2.1%; P = 0.008; and 5.7% vs. 3.4%; P < 0.001, respectively). On multivariable analysis, CPP was associated with increased perioperative mortality (OR 1.47, CI 1.14-1.88, P = 0.003). On Kaplan-Meier analysis, there was no difference in survival at 2 years postdischarge between the NPP and CPP cohorts (86.1% vs. 87.5%, log-rank P = 0.275). CONCLUSIONS:Compromised pelvic perfusion is associated with increased perioperative complications and higher mortality in patients undergoing OAR. The sequelae of losing pelvic perfusion, in addition to the presence of more complex atherosclerotic and aneurysmal disease resulting in more difficult dissection, likely contribute to these findings. Thus, patients considered for OAR who have occluded hypogastric arteries or aneurysmal involvement of the hypogastric artery preoperatively may be candidates for more conservative management beyond traditional size criteria.

OBJECTIVE:The all-comer ClotTriever Outcomes registry assessed indicators of thrombus chronicity in patients with acute, subacute, and chronic lower extremity deep vein thrombosis (DVT). The effectiveness of the ClotTriever System (Inari Medical, Irvine, CA) by chronicity subgroup was also assessed and reported here in this subanalysis. METHODS:All-comer patients with lower extremity DVT were enrolled, with no limitation based on the patients' symptom duration. Chronicity was assessed three times and compared: before the procedure based on symptom duration, during the procedure based on available prethrombectomy imaging, and visual inspection of the extracted thrombus morphology after thrombectomy. Patients were grouped into acute, subacute, and chronic subgroups according to their post-thrombectomy thrombus chronicity based on thrombus morphology. Analyses on baseline and procedural characteristics along with thrombus removal were performed across subgroups. The effectiveness of thrombus removal was determined by Marder scores adjudicated by an independent core laboratory, with a prespecified primary effectiveness end point of complete or near-complete (≥75%) thrombus removal. RESULTS:Of the 260 treated limbs from 250 patients, using symptom duration alone, 70.7% were considered acute, 20.9% subacute, and 8.4% chronic. Upon visual inspection, the extracted thrombus chronicity was approximately one-third in each subgroup: 32.8% had acute thrombus, 34.8% subacute thrombus, and 32.4% chronic thrombus. Chronicity assessed using symptom duration alone mismatched the post-thrombectomy chronicity in 55.1% of limbs (P < .0001) with 49.0% being more chronic than suggested by the patients' duration of symptoms. Chronicity assessed using prethrombectomy imaging mismatched the post-thrombectomy chronicity in 17.5% of limbs (P < .0001). No patients received thrombolytics and 99.6% were treated in a single session. Complete or near-complete thrombus removal was achieved in a high percentage of limbs regardless of thrombus chronicity: 90.8%, 81.9%, and 83.8% in limbs with acute, subacute, and chronic thrombus, respectively. CONCLUSIONS:This subanalysis from the all-comer ClotTriever Outcomes registry demonstrates that extracted thrombus in DVT may be more chronic than suggested by the patients' duration of symptoms. The addition of imaging is helpful to determine the ability of thrombus to respond to therapy. Irrespective of thrombus chronicity, the ClotTriever system can be effective at removing acute, subacute, and chronic thrombus in a single-session procedure without the need for thrombolytics.

BACKGROUND:The impact of pulmonary embolism response teams (PERTs) on treatment choice and outcomes of patients with acute pulmonary embolism (PE) is still uncertain. OBJECTIVE:To determine the effect of PERTs in the management and outcomes of patients with PE. METHODS:PubMed, Embase, Web of Science, CINAHL, WorldWideScience and MedRxiv were searched for original articles reporting PERT patient outcomes from 2009. Data were analysed using a random effects model. RESULTS:16 studies comprising 3827 PERT patients and 3967 controls met inclusion criteria. The PERT group had more patients with intermediate and high-risk PE (66.2%) compared to the control group (48.5%). Meta-analysis demonstrated an increased risk of catheter-directed interventions, systemic thrombolysis and surgical embolectomy (odds ratio (OR) 2.10, 95% confidence interval (CI) 1.74-2.53; p<0.01), similar bleeding complications (OR 1.10, 95% CI 0.88-1.37) and decreased utilisation of inferior vena cava (IVC) filters (OR 0.71, 95% CI 0.58-0.88; p<0.01) in the PERT group. Furthermore, there was a nonsignificant trend towards decreased mortality (OR 0.87, 95% CI 0.71-1.07; p=0.19) with PERTs. CONCLUSIONS:The PERT group showed an increased use of advanced therapies and a decreased utilisation of IVC filters. This was not associated with increased bleeding. Despite comprising more severe PE patients, there was a trend towards lower mortality in the PERT group.