One-year limb salvage and quality of life following mechanical aspiration thrombectomy in patients with acute lower extremity ischemia.

OBJECTIVE: Lower extremity acute limb ischemia (LE-ALI) is associated with high morbidity and mortality rates, and a burden on patient quality of life (QoL). There is limited medium- to long-term evidence on mechanical aspiration thrombectomy (MT) in patients with LE-ALI. The STRIDE study was designed to assess safety and efficacy of MT using the Indigo Aspiration System in patients with LE-ALI. Thirty-day primary and secondary endpoints and additional outcomes were previously published. Here, we report 365-day secondary endpoints and QoL data from STRIDE. METHODS: STRIDE was a multicenter, prospective, single-arm, observational cohort study that enrolled 119 patients across 16 sites in the United States and Europe. Patients were treated first-line with MT using the Indigo Aspiration System (Penumbra, Inc). The study completed follow-up in October 2023. Secondary endpoints at 365 days included target limb salvage and mortality. Additionally, the VascuQoL-6 questionnaire, developed for evaluating patient-centered QoL outcomes for peripheral arterial disease, was assessed at baseline and follow-up through 365 days. RESULTS: Seventy-three percent of patients (87/119) were available for 365-day follow-up. Mean age of these patients was 65.0 ± 13.3 years, and 44.8% were female. Baseline ischemic severity was classified as Rutherford I in 12.6%, Rutherford IIa in 51.7%, and Rutherford IIb in 35.6%. In general, baseline and disease characteristics (demographics, medical history, comorbidities, target thrombus) of these patients are similar to the enrolled cohort of 119 patients. The secondary endpoints at 365 days for target limb salvage was 88.5% (77/87) and mortality rate was 12.0% (12/100). VascuQoL-6 improved across all domains, with a median total score improvement from 12.0 (interquartile range, 9.0-15.0) at baseline to 19.0 (interquartile range, 16.0-22.0) at 365 days. CONCLUSIONS: These 365-day results from STRIDE demonstrate that first-line MT with the Indigo Aspiration System for LE-ALI portray continued high target limb salvage rates and improved patient-reported QoL. These findings indicate Indigo as a safe and effective therapeutic option for LE-ALI.

Use of a novel device for intraoperative wire management during fenestrated endovascular type 4 thoracoabdominal aortic aneurysm repair.

Endovascular procedures are minimally invasive approaches to treat conditions affecting blood vessels without the need for large incisions. The benefits are less blood loss and faster recovery. One condition commonly treated endovascularly is aortic aneurysmal disease often secondary to atherosclerosis or chronic hypertension. As endovascular aneurysm repair becomes increasingly complex and sophisticated, the intraoperative organization and management of wires from multiple access sites becomes paramount. Often, the physician selects visceral or great vessels for delivery of stent grafts to maintain vessel patency. Loss of wire in critical target vessels and wire contamination pose significant patient risks. WireWatch (BioTex Inc. Houston, Texas, USA) is a novel device designed for intraoperative wire management to improve surgical field organization, provide wire stabilization, and prevent dropped wires. This case describes its use in a 73-year-old female undergoing a fenestrated endovascular aneurysm repair of 5.6 cm types IV thoracoabdominal aortic aneurysm.

New Diagnostic Tools for Pulmonary Embolism Detection.

The presentation of pulmonary embolism (PE) varies from asymptomatic to life-threatening, and management involves multiple specialists. Timely diagnosis of PE is based on clinical presentation, D-dimer testing, and computed tomography pulmonary angiogram (CTPA), and assessment by a Pulmonary Embolism Response Team (PERT) is critical to management. Artificial intelligence (AI) technology plays a key role in the PE workflow with automated detection and flagging of suspected PE in CTPA imaging. HIPAA-compliant communication features of mobile and web-based applications may facilitate PERT workflow with immediate access to imaging, team activation, and real-time information sharing and collaboration. In this review, we describe contemporary diagnostic tools, specifically AI, that are important in the triage and diagnosis of PE.

Diagnosis of chronic iliac venous obstruction.

Stenting has become the first line of treatment for symptomatic chronic iliofemoral venous obstruction in patients with quality-of-life-impairing clinical manifestations who have failed conservative therapy. Patient selection for such intervention is, however, dependent on clear identification of relevant clinical manifestations and subsequent testing to confirm the diagnosis. In this regard, the physician engaged in management of such patients needs to be well-aware of symptoms and signs of chronic iliofemoral venous obstruction, and instruments used to grade chronic venous insufficiency and determine quality of life, in addition to diagnostic tests available and their individual roles. This review serves to provide an overview of the diagnosis of chronic iliofemoral venous obstruction and patient selection for stenting.

Diagnosis of chronic iliac venous obstruction

Stenting has become the first line of treatment for symptomatic chronic iliofemoral venous obstruction in patients with quality-of-life impairing clinical manifestations who have failed conservative therapy. Patient selection for such intervention is however dependant on clear identification of relevant clinical manifestations and subsequent testing to confirm the diagnosis. In this regard the physician engaged in management of such patients need to be well aware of symptoms and signs of chronic iliofemoral venous obstruction (CIVO), instruments used to grade chronic venous insufficiency (CVI) and determine quality of life in addition to diagnostic tests available and their individual roles. This review serves to provide an overview of the diagnosis of CIVO and patient selection for stenting.

Intravascular Ultrasound Use in Peripheral Arterial and Deep Venous Interventions: Multidisciplinary Expert Opinion From SCAI/AVF/AVLS/SIR/SVM/SVS.

Percutaneous revascularization is the primary strategy for treating lower extremity venous and arterial disease. Angiography is limited by its ability to accurately size vessels, precisely determine the degree of stenosis and length of lesions, characterize lesion morphology, or correctly diagnose postintervention complications. These limitations are overcome with use of intravascular ultrasound (IVUS). IVUS has demonstrated the ability to improve outcomes following percutaneous coronary intervention, and there is increasing evidence to support its benefits in the setting of peripheral vascular intervention. At this stage in its evolution, there remains a need to standardize the use and approach to peripheral vascular IVUS imaging. This manuscript represents considerations and consensus perspectives that emerged from a roundtable discussion including 15 physicians with expertise in interventional cardiology, interventional radiology, and vascular surgery, representing 6 cardiovascular specialty societies, held on February 3, 2023. The roundtable's aims were to assess the current state of lower extremity revascularization, identify knowledge gaps and need for evidence, and determine how IVUS can improve care and outcomes for patients with peripheral arterial and deep venous pathology.

Safety and efficacy of mechanical aspiration thrombectomy for patients with acute lower extremity ischemia.

OBJECTIVE: Acute limb ischemia (ALI) is associated with high rates of amputation and consequent morbidity and mortality. The objective of this study is to report on the safety and efficacy of aspiration thrombectomy using the Indigo Aspiration System in patients with lower extremity (LE) ALI. METHODS: The STRIDE study was an international, multicenter, prospective, study that enrolled 119 participants presenting with LE-ALI. Patients were treated firstline with mechanical thrombectomy using the Indigo Aspiration System, before stenting or angioplasty, or other therapies as determined by treating physician. The primary end point was target limb salvage at 30 days after the procedure. Secondary end points within 30 days included technical success, defined as core laboratory-adjudicated Thrombolysis in Myocardial Infarction (TIMI) 2/3 flow rate immediately after the procedure, changes in modified Society for Vascular Surgery runoff score, improvement of Rutherford classification compared with before the procedure, patency, rate of device-related serious adverse events, and major periprocedural bleeding. Secondary end points that will be evaluated at 12 months include target limb salvage and mortality. RESULTS: Of the 119 participants enrolled at 16 sites, the mean age was 66.3 years (46.2% female). At baseline (n = 119), ischemic severity was classified as Rutherford I in 10.9%, Rutherford IIa in 54.6%, and Rutherford IIb in 34.5%. The mean target thrombus length was 125.7 ± 124.7 mm. Before the procedure, 93.0% (of patients 107/115) had no flow (TIMI 0) through the target lesion. The target limb salvage rate at 30 days was 98.2% (109/111). The rate of periprocedural major bleed was 4.2% (5/119) and device-related serious adverse events was 0.8% (1/119). Restoration of flow (TIMI 2/3) was achieved in 96.3% of patients (105/109) immediately after the procedure. The median improvement in the modified Society for Vascular Surgery runoff score (before vs after the procedure) was 6.0 (interquartile range, 0.0-11.0). Rutherford classifications also improved after discharge in 86.5% of patients (83/96), as compared with preprocedural scores. Patency at 30 days was achieved in 89.4% of patients (101/113). CONCLUSIONS: In the STRIDE (A Study of Patients with Lower Extremity Acute Limb Ischemia to Remove Thrombus with the Indigo Aspiration System) study, aspiration thrombectomy with the Indigo System provided a safe and effective endovascular treatment for patients with LE-ALI, resulting in a high rate (98.2%) of successful limb salvage at 30 days, with few periprocedural complications.

Venous stent patency is independent of total stented length in nonthrombotic iliac vein and post-thrombotic venous stenoses.

OBJECTIVE: Venous stenting has become the preferred treatment of symptomatic outflow obstruction due to nonthrombotic iliac vein lesions (NIVLs) and post-thrombotic venous stenoses (PTs). A paucity of data exists regarding the effect of stent length on patency rates after intervention. We evaluated the association between stent length and patency in patients treated for iliofemoral venous outflow obstruction. METHODS: The institutional review board approved the present study. A total of 161 patients had undergone venous stenting for NIVLs and thrombotic disease from January 2016 to April 2021. For thrombotic disease, patients with PTs and those with acute deep vein thrombosis (DVT) with underlying outflow obstruction were included. The patient characteristics evaluated included gender, age, body mass index, diagnosed thrombophilia, a history of venous thromboembolism, and CEAP (clinical, etiologic, anatomic, pathophysiologic) score. All the patients had undergone multiplanar venography and intravascular ultrasound during the index procedure. The intravascular ultrasound findings were used to determine the diameter and length of the implanted stents. The patients were placed into two groups, those with stented lengths ≤100 mm and those with stented lengths >100 mm. The primary end point was stent patency between the two groups using duplex ultrasound at 6 months. RESULTS: A total of 108 patients (58.3% female) had had 6-month duplex ultrasound scans available for review. Their mean age was 55.6 ± 17.2 years. The mean body mass index was 31.7 ± 6.9 kg/m2. Overall, the 6-month patency was 89.9%. Of the 108 patients, 56 (51.9%) had had a total stented length of ≤100 mm with a 6-month patency of 92.9%. The remaining 52 patients (48.1%) had had a total stented length >100 mm with a 6-month patency of 86.5%. The rate of patency did not differ significantly between the two groups (P = .222). Stent patency at 6 months for patients with NIVLs was 98% (40 of 41). Stent patency for patients with PTs was 84% (32 of 38). Patency for patients with acute DVT who had undergone stenting after thrombectomy was 86% (25 of 29). Overall, 10 patients with thrombotic disease, including PT and acute DVT, had developed stent thrombosis. The total stented length was not predictive of the loss of patency. CONCLUSIONS: These findings suggest that the length of stent coverage does not confer an increased likelihood of stent thrombosis for patients with iliofemoral venous obstruction. Interventionalists should treat the affected venous segments identified on intravascular ultrasound and effectively stent from normal to normal venous areas, regardless of the stent length required. These results suggest that the total stented length is not a risk factor for stent thrombosis for both NIVL and thrombotic iliofemoral venous lesions.

Novel therapy for recanalization of chronic iliocaval venous occlusion using radiofrequency.

OBJECTIVE: Chronic venous disease of the lower extremities is one of the most common diseases in the United States. The sequelae of this disease process are the source of a significant amount of morbidity, and its prevalence is expected to increase in the coming decades. Interventional therapy is warranted for relief of patients with CEAP C3-C6 disease. With advances in endovascular therapy, chronic iliocaval venous occlusion (CICVO) pathology can be corrected through minimally invasive approaches with limited morbidity and mortality. However, failure to recanalize the venous system leads to high failure rates. The purpose of this study was to assess the procedural success for recanalization of CICVO in the community setting using the novel technique of the Baylis radiofrequency (RF) wire in patients who had failed previous endovascular intervention. METHODS: A retrospective review of patients who underwent RF recanalization for CICVO at our institution from 2019 to 2020 was conducted. All patients had failed previous endovascular attempts at recanalization. The primary outcome was recanalization (defined as restoration of >70% of luminal patency as determined on multiplanar venography [MPV] and intravascular ultrasound [IVUS]) confirmed on both IVUS and MPV. Secondary outcomes included adjunctive interventions and complications (hematoma, pulmonary embolism, new onset renal insufficiency). RESULTS: A total of 10 patients, 50% male with a mean (standard deviation) age of 58.4 (10.4), were evaluated in the study. Successful recanalization was achieved in 60% of cases, with a resolution of >70% of luminal obstruction observed using MPV and IVUS. Adjunctive interventions were performed in 70% of cases. There were no clinically significant complications or blood transfusion requirements. CONCLUSIONS: New techniques and technologies continue to be developed for advanced endovascular management of CICVO, especially with the expanding market for Food and Drug Administration approved venous stents. The Baylis RF wire can assist in recanalization and treatment of patients who had failed previous endovascular therapy.

One-year results of the GORE EXCLUDER Conformable AAA Endoprosthesis system in the United States regulatory trial.

OBJECTIVE: To report the 1-year clinical outcomes from the GORE EXCLUDER Conformable AAA Endoprosthesis system in the US regulatory trial. METHODS: The study is a prospective, multicenter, investigational device exemption clinical trial at 31 US sites with core laboratory assessment of imaging and independent event adjudication. The primary safety (incidence of major adverse events at 30 days) and effectiveness end points (successful aneurysm treatment at 1 year) were assessed in a cohort of patients with abdominal aortic aneurysms (AAAs). RESULTS: We enrolled 80 patients between December 19, 2017, and February, 27, 2019. The mean maximum aortic diameter was 57.7 ± 7.95 mm (range, 42.5-82.7 mm) with an average patient age of 73.5 ± 8.14 years (range, 56-96 years). Overall technical success was 100% (80/80). The mean hospital length stay was 1.2 ± 0.6 days (range, 1-4 days). No primary safety end point events were observed, including no death, stroke, myocardial infarction, bowel ischemia, paraplegia, respiratory failure, renal failure, procedural blood loss of more than 1000 mL, or thromboembolic events including limb occlusion or distal emboli. There were no type I or III endoleaks detected on the 1-, 6-, or 12-month follow-up computed tomography scans. There were no stent fractures, device migrations (≥10 mm), AAA ruptures, or conversions to open surgical repair observed. Two patients had AAA sac growth of more than 5 mm at 1 year owing to type II endoleaks. There were no aneurysm-related deaths within the 12-month follow-up, and freedom from aneurysm-related mortality was 100% through 1 year. CONCLUSIONS: The safety and effectiveness of the GORE EXCLUDER Conformable AAA Endoprosthesis system has been demonstrated with 98.5% freedom from primary effectiveness end point events at 1 year and 100% freedom from primary safety end point events assessed through 30 days.

Comparison of aspiration thrombectomy to other endovascular therapies for proximal upper extremity deep venous thrombosis.

OBJECTIVE: Catheter-directed thrombolysis (CDT) provides an effective method for clearing deep venous thrombosis (DVT). Unfortunately, CDT is associated with hemorrhagic complications. This study evaluated the technical success of the various endovascular therapies including a new mechanical aspiration thrombectomy (AT) device for the treatment of acute upper extremity DVT (UEDVT). METHODS: This single-center retrospective review included patients with acute symptomatic proximal UEDVT secondary to venous thoracic outlet syndrome. Undergoing endovascular therapy from December 2013 to June 2019. Patients were treated with a variety of methods including CDT, ultrasound-assisted thrombolysis (USAT), rheolytic thrombectomy, and AT. We evaluated outcomes for patients undergoing AT compared with nonaspiration thrombectomy (NAT) techniques. The primary outcome was technical success, defined as resolution of more than 70% of the thrombus. The secondary end point was the ability to complete the therapy in a single session. RESULTS: There were 22 patients who had endovascular management of their symptomatic proximal UEDVT. All 22 patients (100%) were successfully treated with more than a 70% thrombus resolution. Ten patients underwent AT, of which 50% (5/10) had single session therapies. Twelve patients underwent NAT (three had CDT or USAT alone; three had USAT with rheolytic thrombectomy; and six had CDT followed by rheolytic thrombectomy), with single session therapy occurring in only 8.3% of the NAT group (1/12). The average total dose of thrombolytics was 12.6 ± 9.65 mg in the AT group compared with 19.0 ± 5.78 mg in the NAT group (mean difference, -6.4; 95% confidence interval, -1.1 to 13.9). All but one of the patients in the AT group went on to have successful first rib resections. All NAT patients had successful first rib resections. A venogram was not performed at the time of decompression. All patients except one underwent resection via the infraclavicular approach, with rib removal posterior to the brachial plexus, a median of 8.0 (interquartile range, 6.0-12.0) days after DVT therapy. CONCLUSIONS: In this study, a technical success rate of 100% was achieved for acute symptomatic proximal UEDVT therapies. AT technology allows for higher rates of treatment in a single session, thereby minimizing a patient's risks of bleeding complications. More research is needed to further define the role of this new technology in the treatment paradigm of UEDVT management.

Technical success and short-term results from mechanical thrombectomy for lower extremity iliofemoral deep vein thrombosis using a computer aided mechanical aspiration thrombectomy device.

BACKGROUND: The symptoms of deep vein thrombosis (DVT) include severe pain and swelling, and the complications can include post-thrombotic syndrome and recurrent venous thromboembolism. Aspiration thrombectomy (AT) treats arterial and venous disease by removing acute thrombus without reliance on thrombolytic agents but also has the potential to remove fresh blood. Intelligent aspiration is designed to minimize blood loss during AT by aspirating continuously in the thrombus but only intermittently when in a patent vascular segment with active flow. The Indigo System with Lightning 12 intelligent aspiration (Penumbra, Inc, Alameda, Calif) uses an automatic valve controlled by a proprietary computer algorithm to optimize thrombus removal and minimize blood loss. This computer-aided mechanical AT (CMAT) system was used for 16 consecutive patients. METHODS: The present retrospective review included 16 patients who had undergone CMAT for iliofemoral acute DVT from July 2020 to June 2021. The primary outcome was >70% thrombus removal as determined by multiplanar venography. The secondary outcomes included single-session therapy, blood loss during aspiration, the need for postprocedure blood transfusion, thrombolytic use, symptom resolution before discharge, and periprocedural complications. RESULTS: Sixteen patients (mean age, 58.6 years; range, 31-80 years; 75.0% women) had undergone CMAT with the Lightning 12 system. All the patients had presented with pain and swelling of 2 to 16 days in duration. No patient had presented with phlegmasia. Access was obtained via the popliteal (n = 11), posterior tibial (n = 3), small saphenous (n = 1), or soleal (n = 1) vein. Thrombus reduction of ≥70% was achieved for all 16 patients (100%). Single-session therapy was successful for 15 patients (93.8%). Eight patients (50%) had received stents. All patients had experienced symptom resolution before discharge. The median blood loss was 155.0 mL (interquartile range, 95.0-187.5), and no patient had required a postprocedure transfusion. One patient had undergone angioplasty after thrombectomy, and one patient (6.2%) had received adjunctive tissue plasminogen activator therapy. No patient had developed postoperative acute kidney failure. No periprocedural complications occurred. At 1 to 8 months of follow-up, 15 of the 16 patients (93.8%) had patency of the treated iliofemoral area, and 14 (87.5%) had no recurrent symptoms. CONCLUSIONS: These results suggest that CMAT using the Lightning 12 system is safe for clot removal for patients with acute iliofemoral DVT with a high rate of single-session technical success and symptom resolution. In the present case series, the Lightning 12 system was also associated with low blood loss, and no patient had required a blood transfusion.

Duplex Ultrasound Surveillance after Transcarotid Artery Revascularization (TCAR) in Clinical Practice.

BACKGROUND: To propose a protocol for the routine clinical use of duplex ultrasound (DUS) assessment after transcarotid artery revascularization (TCAR) procedures, with its specific point of vascular access, based on DUS data from routine clinical practice. METHODS: DUS data were retrospectively collected at 2 centers from a total of 97 patients who underwent a TCAR procedure with at least 30-day and up to 12-month follow-up. Peak systolic velocity (PSV), end diastolic velocity (EDV), and the internal carotid artery (ICA)/common carotid artery (CCA) PSV ratio were collected at baseline (≤30 days after the procedure) and compared with subsequent measurements. RESULTS: Baseline data were established within 30 days after the procedure. There were no access site stenoses, pseudoaneurysms, or dissections detected in follow-up. Average hemodynamics measurements at 12 months after the procedure (36% of patients reached this time point to date) were PSV 167 ± 153 cm/sec, EDV 51 ± 55 cm/sec, and ICA/CCA PSV 2.3 ± 1.9. Five patients (5.2%) exhibited velocities indicative of ≥80% in-stent restenosis (ISR) at 12 months after the procedure. Two patients (2.1%) underwent repeat intervention for ISR based on high velocities and before significant clinical consequence. The other 3 patients (3.1%) were asymptomatic and are being managed medically and monitored for neurological symptoms. One intraprocedural stroke (1.0% of total treated) was observed. CONCLUSIONS: This protocol not only illustrates the utility of using the CCA for the arterial access sheath for carotid stenting, but also successfully identifies patients with clinically significant restenosis >80%-99%. A surveillance regimen of baseline at ≤30 days after the procedure, followed by assessment at 6 and 12 months, and yearly thereafter appears to be a safe and effective protocol, based on the data available to date. A PSV >340 cm/sec and ICA/CCA ratio >4.15 is consistent with an 80-99% restenosis after TCAR. Although a small number, this study serves as a starting point for those who perform TCAR to specifically look at the CCA access site to rule out these potential pitfalls which did occur in the early trials.

Multidisciplinary approach to management of severe lymphedema with one-stage radical excision and split-thickness skin grafting: Report of two cases.

Surgical intervention for severe lymphedema is reserved for failure of conservative management. The reductive approach aims to remove fibrosclerotic tissue acquired from prolonged lymphatic stasis. One such reductive approach is the modified Charles procedure, direct circumferential excision down to fascia followed by split-thickness skin graft application. The 1-year outcomes in our patients suggest that a multidisciplinary approach to the modified Charles procedure is an effective management option for severe lymphedema refractory to conservative therapy.

Transcarotid repair of carotid artery pseudoaneurysm after carotid artery endarterectomy with tandem distal internal carotid artery stenosis.

Pseudoaneurysm development after carotid endarterectomy is a rare occurrence. Even rarer is pseudoaneurysm formation associated with a distal carotid artery stenosis. We report the case of stent grafting of a carotid artery pseudoaneurysm and tandem high-grade distal stenosis through a transcarotid approach with active flow reversal. No reported cases of a transcarotid artery approach to address a carotid artery aneurysm with tandem stenosis were found in the literature. We show that it may be a safe alternative to a transfemoral artery approach or open surgery.

Lower Extremity Revascularization Using Optical Coherence Tomography-Guided Directional Atherectomy: Final Results of the EValuatIon of the PantheriS OptIcal COherence Tomography ImagiNg Atherectomy System for Use in the Peripheral Vasculature (VISION) Study.

PURPOSE: To evaluate the safety and efficacy of a novel optical coherence tomography (OCT)-guided atherectomy catheter in treating patients with symptomatic femoropopliteal disease. METHODS: The VISION trial ( ClinicalTrials.gov identifier NCT01937351) was a single-arm, multicenter, global investigational device exemption study enrolling 158 subjects (mean age 67.2±10.5 years; 87 men) across 20 participating sites. In this cohort, 198 lesions were treated with an average length of 53±40 mm using the Pantheris catheter alone or Pantheris + adjunctive therapy. The primary safety endpoint was the composite of major adverse events (MAEs) through 6 months (objective performance goal 43.2%). Technical success (primary efficacy outcome) was defined as the percent of target lesions with a residual diameter stenosis ≤50% after treatment with the Pantheris device alone (objective performance goal 87.0%). Procedural success was defined as reduction in stenosis to ≤30% after Pantheris ± adjunctive therapy. Tissue specimens retrieved from each treated lesion were histologically analyzed to evaluate the accuracy and precision of OCT image guidance. RESULTS: The primary efficacy outcome was achieved in 192 (97.0%) of the 198 lesions treated with the Pantheris catheter. Across all lesions, mean diameter stenosis was reduced from 78.7%±15.1% at baseline to 30.3%±11.8% after Pantheris alone (p<0.001) and to 22.4%±9.9% after Pantheris ± adjunctive therapy (p<0.001). Of the 198 target lesions, 104 (52.5%) were treated with the Pantheris alone, 84 (42.4%) were treated with Pantheris + adjunctive angioplasty, and 10 (5.1%) with Pantheris + angioplasty + stenting. The composite MAE outcome through 6 months occurred in 25 (16.6%) of 151 subjects. There were no clinically significant perforations, 1 (0.5%) catheter-related dissection, 4 (2%) embolic events, and a 6.4% clinically driven target lesion revascularization rate at 6 months. The 40-lesion chronic total occlusion (CTO) subset (mean lesion length 82±38 mm) achieved a similar significant reduction in stenosis to 35.5%±13.6% after Pantheris alone (p<0.001). Histological analysis of atherectomy specimens confirmed <1% adventitia in 82.1% of the samples, highlighting the precision of OCT guidance. Characterization of the OCT-guided lesions revealed evidence of an underestimation of disease burden when using fluoroscopy. CONCLUSION: OCT-guided atherectomy for femoropopliteal disease is safe and effective. Additionally, the precision afforded by OCT guidance leads to greater removal of plaque during atherectomy while sparing the adventitia.

Initial Experiences with Endovascular Management of Submassive Pulmonary Embolism: Is It Safe?

BACKGROUND: Interventional strategies for massive and submassive pulmonary embolism (smPE) have historically included either systematic intravenous thrombolytic alteplase or surgical embolectomy, both of which are associated with significant morbidity and mortality. However, with the advent of endovascular techniques, recent studies have suggested that an endovascular approach to the treatment of acute smPE may be both safe and effective with excellent outcomes. The purpose of this study was to evaluate the outcomes of patients who have undergone catheter-directed thrombolysis (CDT) for smPE at our institution in an effort to determine the safety of the procedure. METHODS: A retrospective review was conducted from December 2012 to June 2015 to identify patients whom underwent CDT in the treatment of a smPE at our institution. Primary measure was safety of the procedure. Outcome variables were classified as serious or minor adverse events. Serious events included death, stroke, myocardial infarction, and bleeding complications requiring surgical intervention or transfusion. Minor events included groin hematoma, development of arteriovenous fistula, and bleeding requiring interruption or cessation of CDT. In addition, a secondary measure included effectiveness of CDT based on preinterventional and postinterventional clinical examination and radiographic findings. RESULTS: A total of 27 patients undergoing CDT for smPE at our institution were evaluated. The standard procedure included access via bilateral femoral veins and placement of bilateral EKOS catheters for ultrasound-assisted thrombolysis (USAT), with Activase (alteplase) at 1 mg per hour in each catheter for a total of 12 hr. There were no serious adverse events and only 4 patients (14.8%) had minor events, of which only 1 patient required premature termination of therapy due to bleeding resulting in a 3.7% clinically relevant bleeding rate. In addition, a reduction in a right-to-left ventricular end-diastolic diameter ratio (RV/LV ratio) on follow-up imaging was observed in each of the 18 patients where preinterventional and postinterventional imaging was available. Likewise, via chart review, all patients reported significant cessation of shortness-of-breath and resolution of chest pain with associated decrease in supplemental oxygen requirement. CONCLUSIONS: Current evidence, the majority of which has been industry funded, suggests that CDT should be considered as the first-line therapy for smPE. Our experience, in this single-institution retrospective review, demonstrates that CDT with USAT in the treatment of smPE is safe, while providing immediate resolution of both RV strain and clinical symptoms such as shortness-of-breath and chest pain. We hope that these data will allow other institutions to consider CDT as a plausible option in the treatment of smPE.

Venous duplex and pathologic differences in thrombus characteristics between de novo deep vein thrombi and endovenous heat-induced thrombi.

OBJECTIVE: Superficial venous reflux disease has been treated with endovenous ablation techniques for more than 15 years. Thrombi discovered in the postoperative period are referred to as endovenous heat-induced thrombi (EHIT). In spite of the few studies of the ultrasound differentiation between EHIT and deep vein thrombi (DVT), there remains a paucity of literature regarding the evaluation of ultrasound examination and pathologic differentiation. METHODS: Six Yorkshire cross swine underwent femoral vein thrombosis by suture ligation or endovenous radiofrequency ablation. At 1 week after the procedure, each femoral vein was imaged by color Duplex ultrasound and sent for histologic interpretation for differentiation between EHIT and DVT. Five blinded vascular surgery faculty, two vascular surgery fellows, and three vascular surgery residents reviewed the ultrasound images. RESULTS: Thrombi associated with radiofrequency ablation demonstrated a greater degree of hypercellular response, fibroblastic reaction, and edema (3.42 vs 2.92; 3.75 vs 2.42; 2.83 vs 1.33). Specimens harvested from the iatrogenic-induced DVT swine demonstrated a more prolific response to trichrome staining (3.42 vs 2.67). Evidence of revascularization was found in all of the EHIT specimens but in 33% of DVT specimens. On the basis of histologic findings, the pathologist predicted correct modality 92% of the time. Subgroup analysis comparing paired specimens from each swine failed to demonstrate any marked pathologic differences. Recorded ultrasound images from EHIT and DVT samples were reviewed by fellows, residents, and vascular surgery staff to determine whether clot was stationary or free-floating (n = 111; 93%), evidence of retracted or adherent vein (n = 105; 88%), and absence of color flow (n = 102; 85%). The degree of occlusion (partial vs total) and degree of distention of a visualized vein were least likely to be agreed on by reviewers (n = 95; 79% each, respectively). In subgroup (DVT vs EHIT) analyses, the percentage agreement was greatest among vascular surgery fellows (89% and 92%) compared with residents (82% and 79%) and faculty (78% and 77%). CONCLUSIONS: It is possible to differentiate the thrombus origin on pathologic examination but not clinically on ultrasound. Wide variability exists for ultrasound diagnosis of EHIT and de novo DVT. Care must be taken in evaluating post-treatment duplex scans to not assign diagnosis of EHIT when DVT may well be present and extending into the deep venous system. The modulation of collagen production in the treatment of DVT may be helpful in preventing vascular dysfunction and reducing the post-thrombotic changes. Further studies on injury after radiofrequency ablation and laser ablation are needed.