Early Experience With a Novel Dissection-Specific Stent-Graft to Prevent Distal Stent-Graft-Induced New Entry Tears After Thoracic Endovascular Repair of Chronic Type B Aortic Dissections.

BACKGROUND: The aim was to report short and mid-term outcomes of a novel, investigational, dissection-specific stent-graft (DSSG), specifically designed to address the features of chronic type B aortic dissection (CTBAD) and reduce the risk of distal stent-graft-induced new entry tears (dSINE). MATERIALS AND METHODS: A retrospective single center cohort study of all patients undergoing TEVAR with the DSSG for CTBAD from January 1, 2017 to January 31, 2020. The DSSG, which is a modified stent-graft based on the Cook Zenith Alpha Thoracic platform, has no proximal barbs, and a customized longer body length with substantial taper. The second and third distal Z-stents are sited internally to avoid any contact of the metal skeleton with the dissection membrane and have reduced radial force, while the most distal stent was removed creating a distal 30 mm unsupported Dacron graft. RESULTS: Sixteen patients (13 males, 3 females) with a median age of 66 years (range 31-79 years) underwent elective TEVAR of CTBAD using the DSSG. Six patients (38%) had an underlying connective tissue disorder. The median tapering was 10 mm (range 4 mm-21 mm) and median length 270 mm (range 210-380 mm). Technical success was achieved in all but one case (96%). One patient died within 30 days, due to retrograde type A dissection with cardiac tamponade. The 30-day rate of stroke, spinal cord ischemia, and re-interventions was 0%. After median imaging follow-up time of 17 months (range 1-31 months), one patient developed a dSINE 4 months after the index procedure. After median survival follow-up of 23 months (range 2-35 months), one late death occurred due to traumatic brain injury, while no aortic-related death occurred during follow-up. Complete false lumen (FL) thrombosis was achieved in 9 patients while the remaining 6 showed partial FL thrombosis. No instances of diameter increase at the level oftreated aortic segment were noted with serial measurements showing either stable (n = 7) or decreased (n = 8) maximal transverse diameter. CONCLUSIONS: Use of a novel DSSG with low radial force for TEVAR in the setting of CTBAD is safe and feasible. This early real-world experience shows promising mid-term effectiveness with low rates of dSINE or unplanned re-interventions and satisfactory aortic remodeling during follow-up. Longer follow-up is needed, however, before any firm conclusions can be drawn.

Pharmacomechanical thrombectomy for iliofemoral deep vein thrombosis.

BACKGROUND: Deep venous thrombosis (DVT) occurs in approximately one in 1000 adults every year, and has an annual mortality of 14.6%. In particular, iliofemoral DVT can lead to recurrent thrombosis and post-thrombotic syndrome (PTS), a painful condition which can lead to chronic venous insufficiency, oedema, and ulceration. It causes significant disability, impaired quality of life, and economic burden. Early thrombus removal techniques have been advocated in patients with an iliofemoral DVT in order to improve vein patency, prevent valvular dysfunction, and reduce future complications, such as post-thrombotic syndrome and venous ulceration. One such technique is pharmacomechanical thrombectomy, a combination of catheter-based thrombectomy and catheter-directed thrombolysis. OBJECTIVES: To assess the effects of pharmacomechanical thrombectomy versus anticoagulation (alone or with compression stockings), mechanical thrombectomy, thrombolysis, or other endovascular techniques in the management of people with acute DVT of the iliofemoral vein. SEARCH METHODS: The Cochrane Vascular Information Specialist searched the Specialised Register (last searched December 2015) and the Cochrane Register of Studies (last searched December 2015). We searched clinical trials databases for details of ongoing or unpublished studies and the reference lists of relevant articles retrieved by electronic searches for additional citations. SELECTION CRITERIA: Randomised controlled trials in which patients with an iliofemoral deep vein thrombosis were allocated to receive pharmacomechanical thrombectomy versus anticoagulation, mechanical thrombectomy, thrombolysis (systemic or catheter directed thrombolysis), or other endovascular techniques for the treatment of iliofemoral DVT. DATA COLLECTION AND ANALYSIS: At least two review authors independently assessed studies identified for potential inclusion. MAIN RESULTS: We found no randomised controlled trials that met the eligibility criteria for this review. We identified one ongoing study. AUTHORS' CONCLUSIONS: There were no randomised controlled trials that assessed the effects of pharmacomechanical thrombectomy versus anticoagulation (alone or with compression stockings), mechanical thrombectomy, thrombolysis, or other endovascular techniques in the management of people with acute DVT of the iliofemoral vein that met the eligibility criteria for this review. Further high quality randomised controlled trials are needed.

Outcomes After Endovascular Aortic Intervention in Patients With Connective Tissue Disease.

Importance: Endovascular treatment is not recommended for aortic pathologies in patients with connective tissue diseases (CTDs) other than in redo operations and as bridging procedures in emergencies. However, recent developments in endovascular technology may challenge this dogma. Objective: To assess the midterm outcomes of endovascular aortic repair in patients with CTD. Design, Setting, and Participants: For this descriptive retrospective study, data on demographics, interventions, and short-term and midterm outcomes were collected from 18 aortic centers in Europe, Asia, North America, and New Zealand. Patients with CTD who had undergone endovascular aortic repair from 2005 to 2020 were included. Data were analyzed from December 2021 to November 2022. Exposure: All principal endovascular aortic repairs, including redo surgery and complex repairs of the aortic arch and visceral aorta. Main Outcomes and Measures: Short-term and midterm survival, rates of secondary procedures, and conversion to open repair. Results: In total, 171 patients were included: 142 with Marfan syndrome, 17 with Loeys-Dietz syndrome, and 12 with vascular Ehlers-Danlos syndrome (vEDS). Median (IQR) age was 49.9 years (37.9-59.0), and 107 patients (62.6%) were male. One hundred fifty-two (88.9%) were treated for aortic dissections and 19 (11.1%) for degenerative aneurysms. One hundred thirty-six patients (79.5%) had undergone open aortic surgery before the index endovascular repair. In 74 patients (43.3%), arch and/or visceral branches were included in the repair. Primary technical success was achieved in 168 patients (98.2%), and 30-day mortality was 2.9% (5 patients). Survival at 1 and 5 years was 96.2% and 80.6% for Marfan syndrome, 93.8% and 85.2% for Loeys-Dietz syndrome, and 75.0% and 43.8% for vEDS, respectively. After a median (IQR) follow-up of 4.7 years (1.9-9.2), 91 patients (53.2%) had undergone secondary procedures, of which 14 (8.2%) were open conversions. Conclusions and Relevance: This study found that endovascular aortic interventions, including redo procedures and complex repairs of the aortic arch and visceral aorta, in patients with CTD had a high rate of early technical success, low perioperative mortality, and a midterm survival rate comparable with reports of open aortic surgery in patients with CTD. The rate of secondary procedures was high, but few patients required conversion to open repair. Improvements in devices and techniques, as well as ongoing follow-up, may result in endovascular treatment for patients with CTD being included in guideline recommendations.

Randomized controlled trial of dual antiplatelet therapy in patients undergoing surgery for critical limb ischemia.

BACKGROUND AND OBJECTIVE: Patients with critical limb ischemia have a perioperative cardiovascular morbidity comparable to patients with acute coronary syndromes. We hypothesized that perioperative dual antiplatelet therapy would improve biomarkers of atherothrombosis without causing unacceptable bleeding in patients undergoing surgery for critical limb ischemia. METHODS: In a double-blind randomized controlled trial, 108 patients undergoing infrainguinal revascularization or amputation for critical limb ischemia were maintained on aspirin (75 mg daily) and randomized to clopidogrel (600 mg prior to surgery, and 75 mg daily for 3 days; n = 50) or matched placebo (n = 58). Platelet activation and myocardial injury were assessed by flow cytometry and plasma troponin concentrations, respectively. RESULTS: Clopidogrel reduced platelet-monocyte aggregation before surgery (38%-30%; P = 0.007). This was sustained in the postoperative period (P = 0.0019). There were 18 troponin-positive events (8 [16.0%] clopidogrel vs. 10 [17.2%] placebo; relative risk [RR]: 0.93, 95% confidence interval [CI]: 0.39-2.17; P = 0.86). Half of troponin-positive events occurred preoperatively with clopidogrel causing a greater decline in troponin concentrations (P < 0.001). There was no increase in major life-threatening bleeding (7 [14%] vs. 6 [10%]; RR: 1.4, 95% CI: 0.49-3.76; P = 0.56) or minor bleeding (17 [34%] vs. 12 [21%]; RR 1.64, 95% CI: 0.87-3.1; P = 0.12), although blood transfusions were increased (28% vs. 12.6%, RR: 2.3, 95% CI: 1.0-5.29; P = 0.037). CONCLUSIONS: In patients with critical limb ischemia, perioperative dual antiplatelet therapy reduces biomarkers of atherothrombosis without causing unacceptable bleeding. Large-scale randomized controlled trials are needed to establish whether dual antiplatelet therapy improves clinical outcome in high-risk patients undergoing vascular surgery.

Perioperative platelet and monocyte activation in patients with critical limb ischemia.

BACKGROUND: Patients with critical limb ischemia (CLI) have a high rate of adverse cardiovascular events, particularly when undergoing surgery. We sought to determine the effect of surgery and vascular disease on platelet and monocyte activation in vivo in patients with CLI. METHODS: An observational, cross-sectional study was performed at a tertiary referral hospital in the southeast of Scotland. Platelet and monocyte activation were measured in whole blood in patients with CLI scheduled for infrainguinal bypass and compared with matched healthy controls, patients with chronic intermittent claudication, patients with acute myocardial infarction, and those undergoing arthroplasty (n = 30 per group). Platelet and monocyte activation were quantified using flow cytometric assessment of platelet-monocyte aggregation, platelet P-selectin expression, platelet-derived microparticles, and monocyte CD40 and CD11b expression. RESULTS: Compared with those with intermittent claudication, subjects with CLI had increased platelet-monocyte aggregates (41.7% +/- 12.2% vs 32.6% +/- 8.5%, respectively), platelet microparticles (178.7 +/- 106.9 vs 116.9 +/- 53.4), and monocyte CD40 expression (70.0% +/- 12.2% vs 52.4% +/- 15.2%; P < .001 for all). Indeed, these levels were equivalent (P-selectin, 4.4% +/- 2.0% vs 4.9% +/- 2.2%; P > .05) or higher (platelet-monocyte aggregation, 41.7% +/- 12.2% vs 33.6% +/- 7.0%; P < .05; platelet microparticles, 178.7 +/- 106.9 vs 114.4 +/- 55.0/microL; P < .05) than in patients with acute myocardial infarction. All platelet and monocyte activation markers remained elevated throughout the perioperative period in patients with CLI (P < .01) but not those undergoing arthroplasty. CONCLUSIONS: Patients undergoing surgery for CLI have the highest level of in vivo platelet and monocyte activation, and these persist throughout the perioperative period. Additional antiplatelet therapy may be of benefit in protecting vascular patients with more severe disease during this period of increased risk.

Stent-graft induced new entry tears after type B aortic dissection: how to treat and how to prevent?

Progress of aortic disease after stent-graft treatment of aortic dissection includes the risk of stent graft-induced new entry (SINE). In this paper we review the incidence and mechanisms thought to be responsible for retrograde ascending and distal SINE after thoracic endovascular aortic repair (TEVAR) for type B dissection, and examine potential techniques for treatment and prevention. Although the risk of proximal SINE is low, the fatality of this complication requires vigilance in patients who develop new onset symptoms in the early period after TEVAR treatment. Careful technique, minimal oversizing, and use of disease specific stent grafts may reduce the risk for proximal SINE. Distally, SINE is more frequently seen during follow-up in patients treated for chronic dissection. The most important risk factor is oversizing of the stent-graft compared to the true lumen distal landing zone. Development of new disease specific stent grafts with reduced distal radial force may reduce the risk for distal SINE.

In vivo mononuclear cell tracking using superparamagnetic particles of iron oxide: feasibility and safety in humans.

BACKGROUND: Cell therapy is an emerging and exciting novel treatment option for cardiovascular disease that relies on the delivery of functional cells to their target site. Monitoring and tracking cells to ensure tissue delivery and engraftment is a critical step in establishing clinical and therapeutic efficacy. The study aims were (1) to develop a Good Manufacturing Practice-compliant method of labeling competent peripheral blood mononuclear cells with superparamagnetic particles of iron oxide (SPIO), and (2) to evaluate its potential for magnetic resonance cell tracking in humans. METHODS AND RESULTS: Peripheral blood mononuclear cells 1-5 × 10(9) were labeled with SPIO. SPIO-labeled cells had similar in vitro viability, migratory capacity, and pattern of cytokine release to unlabeled cells. After intramuscular administration, up to 10(8) SPIO-labeled cells were readily identifiable in vivo for at least 7 days using magnetic resonance imaging scanning. Using a phased-dosing study, we demonstrated that systemic delivery of up to 10(9) SPIO-labeled cells in humans is safe, and cells accumulating in the reticuloendothelial system were detectable on clinical magnetic resonance imaging. In a healthy volunteer model, a focus of cutaneous inflammation was induced in the thigh by intradermal injection of tuberculin. Intravenously delivered SPIO-labeled cells tracked to the inflamed skin and were detectable on magnetic resonance imaging. Prussian blue staining of skin biopsies confirmed iron-laden cells in the inflamed skin. CONCLUSIONS: Human peripheral blood mononuclear cells can be labeled with SPIO without affecting their viability or function. SPIO labeling for magnetic resonance cell tracking is a safe and feasible technique that has major potential for a range of cardiovascular applications including monitoring of cell therapies and tracking of inflammatory cells. Clinical Trial Registration- URL: http://www.clinicaltrials.gov; Unique identifier: NCT00972946, NCT01169935.