Comparison of aspiration catheter performance using adaptive pulsatile aspiration in an in vitro thrombectomy model

OBJECTIVE

Aspiration with a pump or syringe is a mainstay of mechanical thrombectomy (MT) for acute ischemic stroke (AIS), but this technology has seen minimal evolution. Non-continuous adaptive pulsatile aspiration (APA) has been proposed as a potential alternative to standard continuous aspiration as a means of improving revascularization efficiency.

METHODS

Using a pathophysiological flow bench model with a synthetic clot, we performed in vitro thrombectomies using the ALGO® Von Vascular, Inc. (Sunrise, FL) APA pump. A total of 25 FDA-approved aspiration catheters were tested, representing inner diameters (ID) from 0.035 in. to 0.088 in. The pump was used in 30 trials with each catheter to remove a simulated M1 occlusion. Revascularization, clot ingestion, time to clot removal, and distal embolization were measured.

RESULTS

Among catheters tested using APA, first-pass TICI 3 revascularization was achieved in 100% of the 750 thrombectomy trials using 25 different catheters. There were no distal emboli detected in any trial run. Complete clot ingestion into the pump collection chamber was achieved in 87% to 100% of trials (overall 95%) with clot in the remaining trials corking within the catheter and removed from the model. Time from clot contact to clot removal ranged from 11 s to 90 s (mean 22.6 s, SD 16.8 s), which was negatively correlated with catheter ID (p = 0.007).

CONCLUSION

APA via the Von Vascular, Inc. ALGO® pump achieved a high success rate in an in vitro MT model. All catheters tested with the pump achieved complete reperfusion in all trials, and complete clot ingestion into the pump was seen in a majority of trials. The promising in vitro performance of APA using multiple catheters warrants future in vivo investigation.

[Wild silk: a strong inhalation allergen (author's transl)]

In the course of 18 months, allergic bronchial asthma due to wild silk was diagnosed in 26 patients (19 women, 7 men) of the relatively high mean age at onset of 34 years. In 25 patients the allergy started 1-36 months after acquiring a so-called wild-silk rug, which contains wild-silk waste; one patient fell ill after occupational contact with the waste of wild silk. In all patients the scratch test with wild-silk waste was strongly positive. Elimination of the rug or the occupational exposure made all the symptoms disappear. Wild-silk waste, product of wild-growing oak silkworms, is thus a relatively strong inhalation allergen. Exposure to wild-silk rugs should routinely be considered in the diagnostic work-up of allergies.