Large tube section is the key to successful coronary thrombus aspiration: Findings of a standardized bench test

Assessment of the safety and efficacy of the Zoom 45 and 55 reperfusion catheters for medium and distal mechanical thrombectomies: A multi-institutional study

INTRODUCTION

The Zoom aspiration catheters harbor novel dimensions and construction to enhance trackability and deliverability. In addition, a beveled tip may improve thrombus interaction and aspiration force for a set inner diameter. This study evaluates their utility in medium and distal vessel occlusions.

OBJECTIVE

To evaluate the safety and efficacy of Zoom 45 and 55 aspiration catheters in medium and distal vessel thrombectomy.

METHODS

Patients treated for distal vessel occlusions via mechanical thrombectomy utilizing either the Zoom 45/55 catheter or a historical control catheter between 2021-2022 at two institutions were included in this study. Medium and distal occlusions were defined as any anterior or posterior cerebral artery branch as well as the M2-4 segment of the middle cerebral artery (MCA). Preprocedural, procedural, and postprocedural variables were obtained.

RESULTS

Thirty-eight patients underwent thrombectomy with Zoom 45 or 55 catheters; four had multiple occluded vessels. Occlusion location included the M2 in 32 cases, M3-4 in 7 cases, A2 in 2 cases and P2 in 1 case. The mean number of passes per occlusion was 1.6 and overall successful reperfusion (TICI 2b or greater) was achieved in 84 % of cases. There were no symptomatic procedure-related complications such as perforation or post-procedural symptomatic ICH. Modified Rankin scores rates of 0-2, 3-5, and 6 at three months post-procedure were 35.7 %, 21.4 %, and 42.9 %, respectively.

CONCLUSIONS

The Zoom beveled tip aspiration catheters are safe and effective for more challenging medium and distal vessel occlusions.

In Vitro Comparison of Several Thrombus Removal Tools

BACKGROUND

Although the routine use of thrombus aspiration is not recommended, the thrombectomy technique still might be considered for a selected population of patients. Therefore, the assessment of the effectiveness of commercially available thrombectomy devices is still clinically relevant.

AIM

Here, we present an in vitro comparison of several different types of catheters that can be used for thrombus aspiration or removal.

METHODS

Through the removal of 6 h and 24 h human blood clots in an in vitro model, four catheters were compared: the Launcher, Pronto V4, Vasco+ and the stent-retriever Catchview. The aspiration efficacy was expressed as a percentage of the initial thrombus weight. The effectiveness of the patient's aspiration was dependent on the time of thrombus formation and was significantly higher for a thrombus formed over 24 h (58.5 ± 26.5%) than for one formed over 6 h (48.0 ± 22.5%; p < 0.001). In the presented in vitro model, Pronto V4 and Launcher showed the highest efficiency.

CONCLUSIONS

Large-bore aspiration catheters were found to be more effective than narrow-bore catheters or stent-retrievers in an in vitro model of thrombus removal. The thrombus aspiration efficacy increases with longer thrombus formation times.

Successful visible thrombus aspiration in ST-segment elevation myocardial infarction: associated factors and the clinical impact

BACKGROUND

Thrombus aspiration (TA) has been considered a procedure for controlling distal emboli and improving microvascular perfusion. However, current guidelines classify routine TA as class III recommendation, and it has been reported that the efficacy of TA is limited because of the relatively high incidence of failure in retrieval of thrombotic material. The aim of this study was to explore patient characteristics and procedural factors associated with successful TA in ST-elevation myocardial infarction (STEMI) and to assess the clinical impact of successful TA.

METHODS

This single-center retrospective study enrolled 158 STEMI patients who underwent TA as initial recanalization. Factors associated with successful TA, which was defined as retrieving any visible material by aspiration catheter, were explored, and angiographical and short-term outcomes were assessed.

RESULTS

In 146 cases (92.4%), the aspiration catheter reached the culprit lesion. Successful TA was achieved in 72 cases (45.6%). The single angiographical characteristic of successful TA was a higher Thrombolysis in Myocardial Infarction grade before TA. Among the procedural characteristics, the rate of successful TA was higher with a 7-French aspiration catheter compared with the rate with a 6-French catheter (57.1% vs. 29.9%, P  = 0.01). Thrombolysis in Myocardial Infarction grade 3 flow was more frequent in patients with successful TA immediately after TA (36.1% vs. 16.3%, P  = 0.006) and at final angiography (91.7% vs 79.1%, P  = 0.04) compared with the grade in patients without successful TA, respectively.

CONCLUSIONS

The use of a larger aspiration catheter may be effective in retrieving visible thrombus material, and successful TA led to better angiographical results.

Design of a Flexible Wasp-Inspired Tissue Transport Mechanism

Tissue transport is a challenge during Minimally Invasive Surgery (MIS) with the current suction-based instruments as the increasing length and miniaturisation of the outer diameter requires a higher pressure. Inspired by the wasp ovipositor, a slender and bendable organ through which eggs can be transported, a flexible transport mechanism for tissue was developed that does not require a pressure gradient. The flexible shaft of the mechanism consists of ring magnets and cables that can translate in a similar manner as the valves in the wasp ovipositor. The designed transport mechanism was able to transport 10wt% gelatine tissue phantoms with the shaft in straight and curved positions and in vertical orientation against gravity. The transport rate can be increased by increasing the rotational velocity of the cam. A rotational velocity of 25 RPM resulted in a transport rate of 0.8 mm/s and increasing the rotation velocity of the cam to 80 RPM increased the transport rate to 2.3 mm/s though the stroke efficiency decreased by increasing the rotational velocity of the cam. The transport performance of the flexible transport mechanism is promising. This means of transportation could in the future be an alternative for tissue transport during MIS.

Intracoronary thrombolysis and stentless primary percutaneous coronary intervention in an ectatic right coronary artery with large thrombus burden

A 58-year-old man was admitted to our center with an inferior ST-segment elevation myocardial infarction. A coronary angiogram showed an ectatic right coronary artery (RCA) occluded at mid vessel by a significant clot burden quantified by micro-computed tomography. Guide catheter-directed intracoronary thrombolysis with low-dose tenekteplase resulted in regaining RCA flow, when numerous efforts of manual and 'mother-child' thrombectomy had failed to achieve. A stentless strategy was followed with final thrombolysis in myocardial infarction 3 flow and angiographically insignificant stenosis remaining in the RCA. The combination of intracoronary thrombolysis and a stentless strategy is a safe and effective treatment in ST-segment elevation myocardial infarction patients with ectatic arteries and large thrombus burden when repeat manual aspiration thrombectomy fails.

Efficacy of beveled tip aspiration catheter in mechanical thrombectomy for acute ischemic stroke

Background

Direct aspiration thrombectomy techniques use large bore aspiration catheters for mechanical thrombectomy. Several aspiration catheters are now available. We report a bench top exploration of a novel beveled tip catheter and our experience in treating large vessel occlusions (LVOs) using next-generation aspiration catheters.

Methods

A retrospective analysis from a prospectively maintained database comparing the bevel shaped tip aspiration catheter versus non-beveled tip catheters was performed. Patient demographics, periprocedural metrics, and discharge and 90-day modified Rankin Scale (mRS) scores were collected. Patients were divided into two groups based on which aspiration catheter was used.

Results

Our data showed no significant difference in age, gender, IV tissue plasminogen activator administration, admission NIH Stroke Scale score, baseline mRS, or LVO location between the beveled tip and flat tip groups. With the beveled tip, Thrombolysis in Cerebral Infarction (TICI) 2C or better recanalization was more frequent overall (93.2% vs 74.2%, p=0.017), stent retriever usage was lower (9.1% vs 29%, p=0.024), and patients had lower mRS on discharge (median 3 vs 4, p<0.001) and at 90 days (median 2 vs 4, p=0.008).

Conclusion

Patients who underwent mechanical thrombectomy with the beveled tip catheter had a higher proportion of TICI 2C or better and had a significantly lower mRS score on discharge and at 90 days.

Cardiovascular innovations: Novel mechanical aspiration system to improve thrombus aspiration speed, force, and control

Thrombectomy in coronary arteries and peripheral vasculature is a common procedure performed with electromechanical thrombectomy systems and basic syringe-catheter combinations. Electromechanical systems are associated with speed, power, high-cost, and complexity while basic syringe aspiration systems are associated with ease-of-use, lower cost, and less aspiration force. This report describes a novel mechanical thrombus aspiration system designed to improve aspiration speed and performance plus associated cases studies.

Coronary thrombectomy, technical comparison of two systems on a laboratory bench: the impact of bends, angles and thrombus age

AIMS

Despite the results of recent randomised studies, the systematic use of aspiration techniques in ST-elevation myocardial infarction has not been included in the new guidelines. To date, there have been very few bench tests of the different systems and the aim of our study was to test two catheters on different models of arteries with thrombi at six and 12 hours.

METHODS AND RESULTS

The test apparatus consisted of 3 mm diameter glass tubes of 150 mm in length. The thrombi were left for either six or 12 hours and ten models of tubes were used: straight, with a single bend and with two bends. Two types of catheters were tested: the Export® aspiration catheter (EAC) and the Proxis® embolic protection system (PES). The main assessment criterion was total thrombectomy. Total thrombectomy was achieved in only 55.3% of the tests and no difference appeared between the two systems. Total thrombectomy was achieved more frequently with 6-hour thrombi than with 12-hour thrombi for the two techniques, 62.5% vs. 42.5% (p = 0.018) and 67.5% vs. 48.7% (p = 0.025) for EAC and PES catheter, respectively. In contrast, total thrombectomy was more frequent in straight tubes and in tubes with a single bend than in tubes with double bends, respectively for EAC (64% vs. 44.8%, p = 0.028) and for PES (85.9% vs. 35.4%, p < 0.001).

CONCLUSIONS

The use of thrombectomy in the invasive management of acute coronary syndromes is growing. Our work on a "laboratory bench" reveals important technical differences. In consequence, in clinical practice, we speculate that the catheter system must be chosen according to both the artery anatomy and the delay between chest pain and PCI.

[Impact of the angles and the age of the thrombus on efficacity of thromboaspiration device. A bench study]

INTRODUCTION

Coronary thrombectomy is usually used to treat acute coronary syndrome. Many studies evaluated its benefit in this context however, it is still unknown if coronary characteristics are predictive of success or failure. The aim of our laboratory bench study was to evaluate the impact of angiographic characteristics on the thromboaspiration efficiency.

METHODS

Glass tubes of 150 mm in the length were used, with five diameters: 2; 2.6; 3; 3.6 and 4 mm; and for each diameter, three angulations: no angulation; 90° and 120°. Blood sample were taken from healthy subject and thrombi of 3 and 6 hours old were performed, with a constant volume for each test. Thromboaspirations were performed with an Export(®) catheter (Medtronic). The primary endpoint was total thrombectomy. A total of 240 thromboaspirations were performed.

RESULTS

A total thrombectomy was obtained for 71.2% of the tests. It was achieved more frequently with the smaller diameter, respectively: 100% for 2 mm, 81.3% for 2.6 mm, 89.6% for 3 mm vs 54.2% for 3.6 mm and 31.3% for 4 mm (P<0.001). No differences were observed between the 2 thrombi ages (73.3% for the 3 hours old thrombi and 69.2% for the 6 hours old thrombi, P = 0.476), nor between the three tube's angulations (77.5% for no angle, 66.3% for 90° and 70.0% for 120°, P = 0.278).

RESULTS AND CONCLUSION

This study shows an impact of the coronary diameters on the rate of thromboaspiration success with an Export(®) catheter. Beyond 3 mm of diameter, the rate of success is divided by 2: for diameters less or equal to 3 mm, 90.3% of success vs 42.7% for diameters greater than 3 mm (P<0.001). There is no difference of efficiency between the 3 and 6 hours old thrombi, neither between the tube's angulations. However, this is a preliminary and further works are needed to clarify how to optimize the aspiration and the impact of other catheters.

Direct aspiration using rapid-exchange and low-profile device for acute thrombo-embolic occlusion of the superior mesenteric artery

Acute thrombo-embolic occlusion of the superior mesenteric artery (SMA) is potentially fatal vascular emergency that requires rapid restoration of mesenteric blood flow as well as early diagnosis. Selective thrombolysis has been employed for this life-threatening event. Although failed thrombolysis is a well known phenomenon, which is directly connected with bowel necrosis, emergent laparotomy, and patient death, little progress has been made in its treatment strategy. Recently, direct aspiration using rapid-exchange and low-profile aspiration device has been reported as a simple, safe, and effective strategy to thrombus in coronary artery. We describe the utility of direct aspiration using this sort of aspiration device for failed thrombolysis of SMA thrombo-embolism.