Randomized Trial Comparing a Stent-Avoiding With a Stent-Preferred Strategy in Complex Femoropopliteal Lesions.

BACKGROUND: Limited comparative data exist on different interventional strategies for endovascular revascularization of complex femoropopliteal interventions. OBJECTIVES: In this study, the authors aimed to compare a stent-avoiding (SA) vs a stent-preferred (SP) strategy, promoting optimal lesion preparation and the use of drug-eluting technologies in both arms. METHODS: Within a prospective, multicenter, pilot study, 120 patients with symptomatic complex femoropopliteal lesions (Rutherford classification 2-4, mean lesion length 187.7 ± 78.3 mm, 79.2% total occlusions) were randomly assigned in a 1:1 fashion to endovascular treatment with either paclitaxel-coated balloons or polymer-coated, paclitaxel-eluting stents. Lesion preparation including the use of devices for plaque modification and/or removal was at the operators' discretion in both treatment arms. RESULTS: In the SA group, lesion preparation was more frequently performed (71.7% SA [43/60] vs 51.7% [31/60] SP; P = 0.038) with a high provisional stenting rate (48.3% [29/60]). At the 12-month follow-up, primary patency was 78.2% (43/55) in the SA group and 78.6% (44/56) in the SP group (P = 1.0; relative risk: 0.995; 95% CI: 0.818-1.210). Freedom from major adverse events was determined in 93.1% (54/58) in the SA group and in 94.9% (56/59) in the SP group (P = 0.717; relative risk: 0.981; 95% CI: 0.895-1.075), with all adverse events attributable to clinically driven target lesion revascularization. CONCLUSIONS: Both endovascular strategies promoting lesion preparation before the use of drug-eluting devices suggest promising efficacy and safety results in complex femoropopliteal procedures with a high proportion of total occlusions through 12 months. Ongoing follow-up will show whether different results emerge over time. (Best Endovascular Strategy for Complex Lesions of the Superficial Femoral Artery [BEST-SFA]; NCT03776799).

Abdominal Aortic Endograft Implantation Immediately Induces Vascular Stiffness Gradients That May Promote Adverse Aortic Neck Dilatation: Results of A Porcine Ex Vivo Study.

PURPOSE: Endovascular aortic repair (EVAR) is the method of choice for most abdominal aortic aneurysm (AAA) patients requiring intervention. However, chronic aortic neck dilatation (AND) following EVAR progressively weakens the structural seal between vessel and endograft and compromises long-term results of the therapy. This experimental ex vivo study seeks to investigate mechanisms of AND. MATERIALS AND METHODS: Porcine abdominal aortas (n=20) were harvested from slaughterhouse pigs and connected to a mock circulation. A commercially available endograft was implanted (n=10) or aortas were left untreated as controls (n=10). Vascular circumferential strain was assessed via ultrasound in defined aortic segments as a parameter of aortic stiffness. Histology and aortic gene expression analysis were performed to investigate potential changes of aortic wall structure and molecular differences due to endograft implantation. RESULTS: We found that endograft implantation acutely induces a significant stiffness gradient directly at the interface between stented and unstented aortic segments under pulsatile pressure. Comparing stented aortas with unstented controls, we detected increased aortic expression levels of inflammatory cytokines (Il6 and Ccl2) and matrix metalloproteinases (Mmp2 and Mmp9) after 6 hours of pulsatile pressurization. This effect, however, was abolished when repeating the same experiment under 6 hours of static pressure. CONCLUSIONS: We identified endograft-induced aortic stiffness gradients as an early trigger of inflammatory aortic remodeling processes that might promote AND. These results highlight the importance of adequate endograft designs to minimize vascular stiffness gradients and forestall late complications, such as AND. CLINICAL IMPACT: AND may compromise the long-term results following endovascular aortic repair. However, the mechanisms behind the underlying detrimental aortic remodeling are still unclear. In this study we find that endograft-induced aortic stiffness gradients induce an inflammatory aortic remodeling response consistent with AND. This novel pathomechanistic insight may guide the design of new aortic endografts that minimize vascular stiffness gradients and forestall late complications such as AND.

First Experience With The GoBack-Catheter For Successful Crossing of Complex Chronic Total Occlusions in Lower Limb Arteries.

PURPOSE: To evaluate the use of the GoBack-catheter (Upstream Peripheral Technologies) in complex revascularizations in lower limb arteries. MATERIALS AND METHODS: In this retrospective single-center study, the results of the first 100 consecutive patients including 101 limb-revascularizations, performed between May 2018 and July 2020 with the study device, were analyzed. In all cases, guidewire-crossing failed, and all lesions were chronic total occlusions (CTO), either de novo, reocclusions, or in-stent reocclusions. Successful crossing was defined as passing the CTO using the study device. Patency at discharge and after 30 days was defined as less than 50% restenosis on duplex sonography, without target lesion revascularization. RESULTS: Median lesion length was 24 cm and 38 patients (37.6%) had a calcium grading according to the peripheral arterial calcium scoring system (PACSS) of 4 or 5. In 20.8% of patients, an occluded stent was treated. CTOs involved the femoropopliteal segment in 91.1%, iliac arteries in 5.9%, and tibial arteries in 7.9%. The GoBack-catheter was employed for entering into or crossing through parts or the full length of a CTO or an occluded stent as well as for re-entering into the true lumen after subintimal crossing. The device was used via contralateral and ipsilateral antegrade as well as retrograde access with an overall technical success rate of 92.1%. In 3 patients minor bleeding occurred at the crossing or re-entry site, which were managed conservatively. Thirty-day adverse limb events comprised minor amputations in 4 patients (4.0%), 1 major amputation (1.0%), and reocclusions in 7 limbs (6.9%). CONCLUSION: The new GoBack-catheter offers versatile endovascular applicability for complex CTO recanalization in a broad range of peripheral vascular interventions with a high technical success and low complication rate.

Root cause investigation of a viral contamination incident occurred during master cell bank (MCB) testing and characterization--a case study.

An adventitious agent contamination occurred during a routine 9 CFR bovine viral screening test at BioReliance for an Eli Lilly Chinese Hamster Ovary (CHO) cell-derived Master Cell Bank (MCB) intended for biological production. Scientists from the sponsor (Eli Lilly and Company) and the testing service company (BioReliance) jointly conducted a systematic investigation in an attempt to determine the root cause of the contamination. Our investigation resulted in the identification of the viral nature of the contaminant. Subsequent experiments indicated that the viral contaminant was a non-enveloped and non-hemadsorbing virus. Transmission electron microscopy (TEM) revealed that the viral contaminant was 25-30 nm in size and morphologically resembled viruses of the family Picornaviridae. The contaminant virus was readily inactivated when exposed to acidic pH, suggesting that the viral contaminant was a member of rhinoviruses. Although incapable of infecting CHO cells, the viral contaminant replicated efficiently in Vero cell with a life cycle of approximately 16 h. Our investigation provided compelling data demonstrating that the viral contaminant did not originate from the MCB. Instead, it was introduced into the process during cell passaging and a possible entry point was proposed. We identified the viral contaminant as an equine rhinitis A virus using molecular cloning and DNA sequencing. Finally, our investigation led us to conclude that the source of the viral contaminant was the equine serum added to the cell growth medium in the 9 CFR bovine virus test.