Comparison of vacuum pressures and suction forces generated by different pump systems for aspiration thrombectomy

Comparison of clinical, technical, and safety outcomes between the Sofia 5Fr catheter vs. the Sofia 6Fr catheter; a MaSQ-Registry study

BACKGROUND

Direct aspiration during endovascular treatment (EVT) for acute ischemic stroke (AIS) patients is safe and effective. The 'Soft torqueable catheter Optimized For Intracranial Access' (Sofia) catheter is commonly used. Data on differences between 5Fr and 6Fr Sofia is limited. Hence, we aimed to compare the clinical, technical, and safety outcomes between both Sofia catheters in AIS patients.

METHODS

Patients with an intracranial anterior circulation occlusion from the 'Maastricht Stroke Quality-registry' (MaSQ-registry), who underwent EVT for AIS from September 2020 to February 2023, and treated with the Sofia catheter in the first-line technique were included. Outcomes included a shift on the modified Rankin Scale (mRS) score at 90 days, favorable functional outcome (mRS 0-2), first-attempt recanalization rate, and per procedural complications. Multivariable regression analyses were performed with adjustments.

RESULTS

Out of 511 registered patients in the MaSQ-registry, 366 patients were included. 281 patients (77 %) were treated with the Sofia 6Fr. No shift towards better outcomes on the ordinal mRS score at 90 days was observed in the Sofia 6Fr group compared to the 5Fr (adjusted common[ac] OR:1.34, 95 %CI:0.70-2.56). Favorable functional outcome (aOR:1.24, 95 %CI:0.49-3.13), and per procedural complications (aOR:1.04, 95 %CI:0.41-2.64) did not differ significantly between Sofia 6Fr and 5Fr. The Sofia 6Fr achieved higher first-attempt successful recanalization rates (53 % versus 34 %; aOR:2.28, 95 %CI:1.11-4.69), and lower total thrombectomy attempts (median:1 versus 2; aβ:-0.63, 95 %CI:-1.21 to -0.05).

CONCLUSIONS

The use of 6Fr Sofia aspiration catheter leads in this single-center registry to higher first-attempt successful recanalization rates and fewer thrombectomy attempts compared to the 5Fr Sofia catheter. However, this did not reflect in better clinical outcomes.

The use of a (non-) balloon guide catheter in endovascular stroke treatment, a registry of real-life use and nationwide questionnaire

INTRODUCTION

Despite literature suggesting benefits of a balloon guide catheter (BGC) in stroke thrombectomy, BGCs are not routinely used. This study aimed to get insights in the use of a BGC and the reasons (not) to inflate the balloon.

METHODS

Data were used of the Maastricht Stroke Quality Registry (MaSQ-Registry), a prospective registry for quality purposes of stroke patients treated between September 2020-February 2023. Additionally, a Dutch nationwide questionnaire was sent among all stroke treating physicians of the Dutch Society of Interventional Radiology (NVIR). Information on the use and reasons for selecting a (non-)BGC and using the BGC was collected.

RESULTS

Out of 511 patients registered in the MaSQ-Registry, 458 were included. In 69% (n=317) of the patients a BGC was used; in 68% (n=214) the balloon was not inflated. In 95% of the posterior circulation occlusions a non-BGC was used. In total 47 treating physicians from sixteen stroke centers responded to the questionnaire. 51% (n=24) preferred a non-BGC and 30% (n=14) never used a BGC. 52% and 18% of the BGC-users estimated they inflate the balloon in 80-100% and 0-20% of the times, respectively. The main reasons reported for not inflating the balloon were when the BGC was occlusive (47%) or not placeable (34%) in the carotid artery.

CONCLUSION

This study shows variation in the use of (non-)BGC use with and without inflated balloon among treating physicians in the Netherlands, highlighting current limited consensus regarding the use of (non-)BGCs among stroke treating physicians.

Optimizing suction force in mechanical thrombectomy: Priming the aspiration tubing with air versus saline

OBJECTIVE

We sought to investigate how priming the tube between air versus air mixed with saline ex vivo influenced suction force. We examined how priming the tube influenced peak suction force and time to achieve peak suction force between both modalities.

METHODS

Using a Dwyer Instruments (Dwyer Instruments Inc., Michigan City, IN, USA), INC Digitial Pressure Gauge, we were able to connect a .072 inch aspiration catheter to a rotating hemostatic valve and to aspiration tubing. We recorded suction force measured in negative inches of Mercury (inHg) over 10 iterations between having the aspiration tube primed with air alone versus air mixed with saline. A test was used to compare results between both modalities.

RESULTS

Priming the tube with air alone compared to air mixed with saline was found to have an increased average max suction force (-28.60 versus -28.20 in HG, p<0.01). We also identified a logarithmic curve of suction force across time in which time to maximal suction force was more prompt with air compared with air mixed with saline (13.8 seconds versus 21.60 seconds, p<0.01).

CONCLUSIONS

Priming the tube with air compared to air mixed with saline suggests that not only is increased maximal suction force achieved, but also the time required to achieve maximal suction force is less. This data suggests against priming the aspiration tubing with saline and suggests that the first pass aspiration primed with air may have the greatest suction force.

Current Approaches and Methods to Understand Acute Ischemic Stroke Treatment Using Aspiration Thrombectomy

Acute ischemic stroke occurs when a blood clot occludes a cerebral artery. Mechanical interventions, primarily stent retrievers and aspiration thrombectomy, are used currently for removing the occluding clot and restoring blood flow. Aspiration involves using a long catheter to traverse the cerebral vasculature to reach the blood clot, followed by application of suction through the catheter bore. Aspiration is also used in conjunction with other techniques such as stent retrievers and balloon guide catheters. Despite the wide use of aspiration, our physical understanding of the process and the causes of the failure of aspiration to retrieve cerebral clots in certain scenarios is not well understood. Experimental and computational studies can help develop the capability to provide deeper insights into the procedure and enable development of new devices and more effective treatment methods. We recapitulate the aspiration-based thrombectomy techniques in clinical practice and provide a perspective of existing engineering methods for aspiration. We articulate the current knowledge gap in the understanding of aspiration and highlight possible directions for future engineering studies to bridge this gap, help clinical translation of engineering studies, and develop new patient-specific stroke therapy.

Comparative analysis of syringes versus pump devices in benchtop aspiration thrombectomy models: A systematic review and meta-analysis

BACKGROUND

Although direct contact aspiration has emerged as one of the leading techniques for mechanical thrombectomy (MT), there is still ongoing debate about the aspiration/suction pump devices that can optimize recanalization rates. To address this gap, we conducted a meta-analysis comparing the aspiration efficacy of 60 ml syringe and pump devices in benchtop MT models.

METHODS

Systematic literature review was conducted using Medline, Embase, Web of Science, and Scopus in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Outcomes of interest included flow rate and vacuum pressure delivered by a 60 ml syringe and several aspiration pumps. We used a random effects model to calculate the mean difference (MD) with 95% confidence intervals (CIs) and a statistically significant difference was considered as a two-sided p-value of less than 0.05.

RESULTS

We included six benchtop studies comparing 60 ml syringes and vacuum pumps. Our meta-analysis showed that there were no significant differences in vacuum pressure (MD:0.71inHg, 95% CI: [-0.81;2.23], p = 0.359) and flow rate (MD:0.27 mL/s, 95% CI: [-3,07; 3.61], p = 0.873) between 60 ml syringes and vacuum pumps groups.

CONCLUSIONS

Our study demonstrated comparable performance in terms of vacuum pressure and flow rates between a 60 ml syringe and a heterogeneous combination of commercially available aspiration pumps.