Prospective multicenter study of a novel endovascular venous anastomotic procedure and device for implantation of an arteriovenous graft for hemodialysis.

INTRODUCTION: The traditional sutured venous anastomosis used during arteriovenous graft implantation is associated with a high incidence of subsequent stenosis that is attributed to neointimal hyperplasia. Hyperplasia results from multiple factors, including hemodynamic abnormalities and vessel trauma during implantation. A novel anastomotic connector device was designed to provide an alternative, less traumatic, endovascular venous anastomosis that may ameliorate the clinical challenges associated with a sutured anastomosis. A prospective single-arm multicenter study was performed to evaluate safety and effectiveness of graft implantation using the study device. METHODS: Patients requiring graft creation and who met the study criteria were enrolled between February 2018 and July 2021 and observed for 6 months. Collected data included baseline characteristics, graft patency and use for hemodialysis, graft interventions, and adverse events. The primary study endpoint was cumulative graft patency, compared to a pre-specified Performance Goal of 75%. Secondary endpoints included primary unassisted patency and serious adverse events, defined as the occurrence of death, graft infection, emergent surgery, significant bleeding, and pseudoaneurysm. RESULTS: A total of 158 patients were enrolled from 10 study sites, among which 144 subjects were evaluable at 6 months and 14 were censored with partial follow-up observation. Three patients died and the graft was abandoned in 12. The primary endpoint was met (p-value < 0.001). By Kaplan Meier survival analysis, cumulative patency was 92.08% with a lower 95% Confidence Bound of 86.98%. Primary unassisted patency was 60.21% with a lower 95% Confidence Bound of 50.84%. Graft infections occurred in six patients, all unrelated to the study device. There were no reports of emergent surgery, significant bleeding or pseudoaneurysm. CONCLUSION: These results demonstrate that the study device can be used for successful endovascular anastomosis of a vein to a graft for hemodialysis, with acceptable cumulative patency and safety profile at 6 months. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02532621.

Transcatheter anastomosis connector system for vascular access graft placement: results from a first-in-human pilot study.

PURPOSE: A lengthy healing and maturation period follows standard surgical preparation of a permanent arteriovenous access, often requiring or extending use of a venous catheter (VC) for hemodialysis. The InterGraft™ Anastomotic Connector System was developed for minimally invasive anastomosis of an arteriovenous graft (AVG). The venous and arterial InterGraft™ connectors are designed to provide optimized flow dynamics and may result in reduction of AVG stenosis. This pilot study evaluated placement procedure success, patency and safety of the InterGraft™ connectors. METHODS: Nine AVGs were implanted in nine patients currently receiving dialysis with a VC. The study allowed use of both connectors (n = 5) or use of the venous connector with a sutured arterial anastomosis (n = 4). Monthly ultrasound examinations were performed throughout the six-month follow-up. AVG angiography was performed at five months. Endpoints included procedure success (acceptable graft flow at end of procedure, without significant bleeding or need for emergent surgery), patency, and device-related major adverse events. RESULTS: Procedure success was attained in all patients. AVGs were used for dialysis within 17 days, on average, and VCs were removed. Three patients exited the study early for reasons unrelated to the InterGraft™ connectors. The remaining six patients had patent grafts: two with assisted and four with unassisted patency. AVG flow rates were greater than 1 L/minute. No dilatations or aneurysms were observed by angiography. There were no device-related major adverse events. CONCLUSIONS: The InterGraft™ connectors can be safely and successfully used for AVG anastomoses, with acceptable near-term patency. Further clinical evaluation is warranted.

Treatment of non-traumatic out-of-hospital cardiac arrest with active compression decompression cardiopulmonary resuscitation plus an impedance threshold device.

BACKGROUND: A recent out-of-hospital cardiac arrest (OHCA) clinical trial showed improved survival to hospital discharge (HD) with favorable neurologic function for patients with cardiac arrest of cardiac origin treated with active compression decompression cardiopulmonary resuscitation (CPR) plus an impedance threshold device (ACD+ICD) versus standard (S) CPR. The current analysis examined whether treatment with ACD+ITD is more effective than standard (S-CPR) for all cardiac arrests of non-traumatic origin, regardless of the etiology. METHODS: This is a secondary analysis of data from a randomized, prospective, multicenter, intention-to-treat, OHCA clinical trial. Adults with presumed non-traumatic cardiac arrest were enrolled and followed for one year post arrest. The primary endpoint was survival to hospital discharge (HD) with favorable neurologic function (Modified Rankin Scale score ≤ 3). RESULTS: Between October 2005 and July 2009, 2738 patients were enrolled (S-CPR=1335; ACD+ITD=1403). Survival to HD with favorable neurologic function was greater with ACD+ITD compared with S-CPR: 7.9% versus 5.7%, (OR 1.42, 95% CI 1.04, 1.95, p=0.027). One-year survival was also greater: 7.9% versus 5.7%, (OR 1.43, 95% CI 1.04, 1.96, p=0.026). Nearly all survivors in both groups had returned to their baseline neurological function by one year. Major adverse event rates were similar between groups. CONCLUSIONS: Treatment of out-of-hospital non-traumatic cardiac arrest patients with ACD+ITD resulted in a significant increase in survival to hospital discharge with favorable neurological function when compared with S-CPR. A significant increase survival rates was observed up to one year after arrest in subjects treated with ACD+ITD, regardless of the etiology of the cardiac arrest.

Rheolytic thrombectomy with percutaneous coronary intervention for infarct size reduction in acute myocardial infarction: 30-day results from a multicenter randomized study.

OBJECTIVES: The goal of this work was to determine whether rheolytic thrombectomy (RT) as an adjunct to primary percutaneous coronary intervention (PCI) reduces infarction size and improves myocardial perfusion during treatment of ST-segment elevation myocardial infarction (STEMI). BACKGROUND: Primary PCI for STEMI achieves brisk epicardial flow in most patients, but myocardial perfusion often remains suboptimal. Distal embolization of thrombus during treatment may be a contributing factor. METHODS: This prospective, multicenter trial enrolled 480 patients presenting within 12 h of symptom onset and randomized to treatment with RT as an adjunct to PCI (n = 240) or to PCI alone (n = 240). Visible thrombus was not required. The primary end point was infarct size measured by sestamibi imaging at 14 to 28 days. Secondary end points included final Thrombolysis In Myocardial Infarction (TIMI) flow grade, tissue myocardial perfusion (TMP) blush, ST-segment resolution, and major adverse cardiac events (MACE), defined as the occurrence of death, new Q-wave myocardial infarction, emergent coronary artery bypass grafting, target lesion revascularization, stroke, or stent thrombosis at 30 days. RESULTS: Final infarct size was higher in the adjunct RT group compared with PCI alone (9.8 +/- 10.9% vs. 12.5 +/- 12.13%; p = 0.03). Final TIMI flow grade 3 was lower in the adjunct RT group (91.8% vs. 97.0% in the PCI alone group; p < 0.02), although fewer patients had baseline TIMI flow grade 3 in the adjunct RT group (44% vs. 63% in the PCI alone group; p < 0.05). There were no significant differences in TMP blush scores or ST-segment resolution. Thirty-day MACE was higher in the adjunct RT group (6.7% vs. 1.7% in the PCI alone group; p = 0.01), a difference primarily driven by very low mortality rate in patients treated with PCI alone (0.8% vs. 4.6% in patients treated with adjunct RT; p = 0.02). CONCLUSIONS: Despite effective thrombus removal, RT with primary PCI did not reduce infarct size or improve TIMI flow grade, TMP blush, ST-segment resolution, or 30-day MACE.

Characterization of alteplase (tPA) following delivery through the AngioJet rheolytic catheter.

PURPOSE: To analyze alteplase solutions following delivery through the AngioJet Xpeedior rheolytic thrombectomy device to characterize the viability of proteins exposed to high shear stress. METHODS: Alteplase solutions were prepared by reconstitution in sterile water to obtain a targeted concentration of 1.0 mg/mL. A baseline control sample was obtained. The AngioJet system was modified by occluding the return line to allow collection of the dispersed fluid volume. Alteplase solutions (n=5) were delivered through the 6-F, 120-cm Xpeedior catheter and collected. All samples were assayed and compared to baseline using qualitative visual inspection, ultraviolet spectrophotometry, size exclusion chromatography, and in vitro clot lysis assays. RESULTS: Analysis of the test solutions demonstrated a mean protein recovery of 98.0%+/-3.5% of targeted concentration; the collected protein was fully active, as determined by clot lysis assays (specific activity > or =100%). All samples were clear and colorless. No significant fragmentation or aggregation of protein was observed. CONCLUSIONS: Alteplase solutions, when delivered through the AngioJet Xpeedior rheolytic thrombectomy device, remain stable and biologically active in vitro. Further clinical investigation is warranted using this method as a novel approach for pharmacomechanical thrombolysis.

Treatment of coronary stent thrombosis with rheolytic thrombectomy: results from a multicenter experience.

The objective of this study was to assess the feasibility, efficacy, and safety of rheolytic thrombectomy (RT) for treatment of coronary stent thrombosis. Stent thrombosis is an infrequent but potentially devastating complication. Conventional treatment with balloon angioplasty and/or thrombolysis has yielded suboptimal results. RT was used to treat 18 patients (mean age, 62 +/- 8 years; 72% male) with in-stent thrombosis (mean time to stent thrombosis, 2.4 +/- 1.8 days). Device success, procedure success, in-hospital and 30-day major cardiovascular events (MACE) were assessed in the hospital and at 30 days. Device success was obtained in 94% and procedure success was achieved in 100% of patients. Following RT, 11 patients underwent balloon angioplasty and 7 patients received additional stents. TIMI 3 coronary flow was obtained in 94.4% and all (100%) patients achieved either TIMI 2 or 3 coronary flow. The angiographic thrombus area decreased from 113.7 +/- 79 to 5.5 +/- 5.7 mm(2) after RT, and to 0.9 +/- 2.1 mm(2) (P < 0.001) after final treatment. Procedural complications were limited to transient no-reflow in five patients. Only one patient evolved a Q-wave MI. At 30 days of follow-up, no patients suffered death, emergent bypass surgery, or stroke. Our data suggest that the adjunctive use of rheolytic thrombectomy offers improved outcomes compared to prior results of intervention after coronary stent thrombosis and should be strongly considered as a treatment option for this complication.