Suction force rather than aspiration flow correlates with recanalization in hard clots: an in vitro study model.

BACKGROUND: ANA Advanced Neurovascular Access provides a novel funnel component designed to reduce clot fragmentation and facilitate retrieval in combination with stent-retrievers (SRs) in stroke patients by restricting flow and limiting clot shaving. In previous publications ANA presented excellent in vitro/in vivo efficacy data, especially with fibrin-rich hard clots. We aimed to determine the main physical property responsible for these results, namely suction force versus aspiration flow. METHODS: We evaluated in a bench model the suction force and flow generated by ANA and compared them to other neurovascular catheters combined with a SR (Solitaire). Aspiration flow was evaluated with a flow rate sensor while applying vacuum pressure with a pump. Suction force was determined using a tensile strength testing machine and a purposely designed tool that completely seals the device tip simulating complete occlusion by a hard clot. Suction force was defined as the force needed to separate the device from the clot under aspiration. All experiments were repeated five times, and mean values used for comparisons. RESULTS: Aspiration flow increased with the inner diameter of the device: ANA 1.85±0.04 mL/s, ACE68 3.74±0.05 mL/s, and 8F-Flowgate2 5.96±0.30 mL/s (P<0.001). After introducing the SR, the flow was reduced by an average of 0.57±0.12 mL/s. Due to its larger distal surface, ANA suction force (1.69±0.40 N) was significantly higher than ACE68 (0.26±0.04 N) and 8F-Flowgate2 (0.42±0.06 N) (P<0.001). After introducing the SR, suction force variation was not relevant except for ANA that increased to 2.64±0.41 N. CONCLUSION: Despite lower in vitro aspiration flow, the ANA design showed a substantially higher suction force than other thrombectomy devices.

[Osteoarticular infection diagnosis]. / Moyens diagnostiques des infections ostéo-articulaires.

Diagnosis of osteitis/arthritis requires clinical, microbiological and radiological data. Good quality samples must be obtained before antibiotic therapy is introduced to identify causative microorganisms. New technical methods such as PCR can improve the diagnosis. X-ray radiograph is always performed when osteitis is suspected, even if the diagnosis can be difficult since abnormalities are present late in the course of the disease. MRI is the best method to establish the diagnosis of osteitis or arthritis. Scintigraphy can be an interesting investigation since it can be promptly performed even in patients with foreign material. New technical such as PET-Scan could be interesting to establish the diagnosis. Collaboration between clinicians, microbiologists and radiologists is essential to establish the diagnosis in order to target the appropriate treatment and to improve the prognosis.