Safety and Effectiveness of Neuro-thrombectomy on Single compared to Biplane Angiography Systems

World Federation for Interventional Stroke Treatment (WIST) Multispecialty Training Guidelines for Endovascular Stroke Intervention

INTRODUCTION

Today, endovascular treatment (EVT) is the therapy of choice for strokes due to acute large vessel occlusion, irrespective of prior thrombolysis. This necessitates fast, coordinated multi-specialty collaboration. Currently, in most countries, the number of physicians and centres with expertise in EVT is limited. Thus, only a small proportion of eligible patients receive this potentially life-saving therapy, often after significant delays. Hence, there is an unmet need to train a sufficient number of physicians and centres in acute stroke intervention in order to allow widespread and timely access to EVT.

AIM

To provide multi-specialty training guidelines for competency, accreditation and certification of centres and physicians in EVT for acute large vessel occlusion strokes.

MATERIAL AND METHODS

The World Federation for Interventional Stroke Treatment (WIST) consists of experts in the field of endovascular stroke treatment. This interdisciplinary working group developed competency - rather than time-based - guidelines for operator training, taking into consideration trainees' previous skillsets and experience. Existing training concepts from mostly single specialty organizations were analysed and incorporated.

RESULTS

The WIST establishes an individualized approach to acquiring clinical knowledge and procedural skills to meet the competency requirements for certification of interventionalists of various disciplines and stroke centres in EVT. WIST guidelines encourage acquisition of skills using innovative training methods such as structured supervised high-fidelity simulation and procedural performance on human perfused cadaveric models.

CONCLUSIONS

WIST multispecialty guidelines outline competency and quality standards for physicians and centres to perform safe and effective EVT. The role of quality control and quality assurance is highlighted.

SUMMARY

The World Federation for Interventional Stroke Treatment (WIST) establishes an individualized approach to acquiring clinical knowledge and procedural skills to meet the competency requirements for certification of interventionalists of various disciplines and stroke centres in endovascular treatment (EVT). WIST guidelines encourage acquisition of skills using innovative training methods such as structured supervised high-fidelity simulation and procedural performance on human perfused cadaveric models. WIST multispecialty guidelines outline competency and quality standards for physicians and centers to perform safe and effective EVT. The role of quality control and quality assurance is highlighted.

SIMULTANEOUS PUBLICATION

The WIST 2023 Guidelines are published simultaneously in Europe (Adv Interv Cardiol 2023).

Occupational radiation exposure of neurointerventionalists during endovascular stroke treatment

BACKGROUND

Radiological neuro-interventions, especially endovascular stroke treatment (EST), are increasing in case numbers worldwide with increasing occupational radiation exposure. Aim of this study was to define the radiation exposure of neurointerventionalists (NI) during EST and to compare the accumulated dose reaching the left arm with the left temple.

METHODS

This is a prospective observational study in a tertiary stroke center conducted between 11/2021 and 07/2022. Radiation exposure was measured using real time dosimetry with dosimeters being carried by the NI during EST simultaneously at the left temple and left arm. The effective dose [µSV] per dose area product (DAP) and potential influencing factors were compared in univariate analysis between the two dosimeter positions.

RESULTS

In total, 82 ESTs were analyzed with a median DAP of 6179 µGy*m² (IQR 3271 µGy*m²-11720 µGy*m²). The accumulated dose at the left arm and left temple correlated with the DAP and fluoroscopy time of the EST (DAP and arm: p = 0.01, DAP and temple: p = 0.006). The radiation exposure (RE) showed a wide range and did not differ between the two dosimeter positions (median, IQR arm 7 µSV, IQR 3.1-16.9 µSV, min. 0.3 µSV max. 64.5 µSV) vs. head 7 µSv, IQR 3.2-17.4 µSV, min. 0.38 µSV, max. 48.6 µSV, p = 0.94). Occupational RE depends on the number of thrombectomy attempts, but not the target vessel occlusion location or the NI's body height.

CONCLUSION

Neurointerventionalists experience a generally low but very variable radiation exposure during EST, which depends on the intervention's fluoroscopy time and dose area product as well as thrombectomy attempts but does not differ between left temple and left arm.

Monoplane versus biplane fluoroscopy in patients undergoing fenestrated/branched endovascular aortic repair

OBJECTIVE

Endovascular aortic repair (EVAR) with fenestrated (F-EVAR) or branched (B-EVAR) endografts represents an indispensable tool of modern patient care in vascular surgery. The purpose of this retrospective study was to evaluate the center's initial experience of F/B-EVAR procedures performed under biplane angiography guidance compared with a historical control group.

METHODS

From January 2020 to March 2022, 80 consecutive patients underwent F/B-EVAR under general anesthesia at a single institution. As from January 2021, the deployment of complex stent grafts was performed using an alternative intraoperative imaging modality-a biplane fluoroscopy and angiography. The cohort was divided into monoplane (MPA) and biplane (BPA) groups according to the imaging modality applied. The end points were operation time, fluoroscopy time, radiation exposure, dose of contrast agent, and technical success.

RESULTS

The MPA group included 59 patients (78% male; median age; 74 years; interquartile range [IQR], 66-78 years) and the BPA group 21 patients (85.7% males; median age, 75 years; IQR, 69-79 years). Operation time (median, 320 minutes; IQR, 266-376 minutes) versus (median, 275 minutes; IQR, 216-333 minutes) was significantly lower in the BPA group (P = .006). The median fluoroscopy time (median, 82 minutes; IQR, 57-110 minutes vs median, 68 minutes; IQR, 54-92 minutes), contrast agent volume applied (median, 220 mL; IQR, 179-250 mL vs median, 200 mL; IQR, 170-250 mL), and radiation dose (dose-area product, median, 413 Gy × cm²; IQR, 249-736 Gy × cm²; vs median, 542 Gy × cm²; IQR, 196-789 Gy × cm²) were similar in both groups. Technical success of 96.6% (57/59 cases) versus 100% (21/21 cases) could be achieved in MPA and BPA group, respectively.

CONCLUSIONS

F/B-EVAR procedures performed under BPA guidance were associated with a significant decrease in operation time.

Modeling optimal patient transport in a stroke network capable of remote telerobotic endovascular therapy

BACKGROUND

Telerobotic endovascular therapy (EVT) has the potential to decrease time to treatment and expand existing networks of care to more rural populations. It is currently unclear how its implementation would impact existing stroke networks.

METHODS

Conditional probability models were generated to predict the probability of excellent outcome for patients with suspected large vessel occlusion (LVO). A baseline stroke network was created for California using existing intravenous thrombolysis (IVT) centers and comprehensive stroke centers (CSCs) capable of IVT and EVT. Optimal transport decisions and catchment areas were generated for the baseline model and three hypothetical scenarios through conversion of IVT centers at various distances from a CSC into centers capable of telerobotic EVT [i.e., hospitals ≥15 and <50 miles from a CSC were converted (Scenario 1), ≥50 and <100 miles (Scenario 2), and ≥100 miles (Scenario 3)]. Procedural times and success rates were varied systematically.

RESULTS

Telerobotic EVT centers decreased median travel time for LVO patients in all three scenarios. The estimated number of robotically treated LVOs per year in Scenarios 1, 2, and 3 were 2,172, 740, and 212, respectively. Scenario 1 (15-50 miles) was the most sensitive to robotic time delay and success rate, but all three scenarios were more sensitive to decreases in procedural success rate compared to time delay.

CONCLUSIONS

Telerobotic EVT has the potential to improve care for stroke patients outside of major urban centers. Compared to procedural time delays in robotic EVT, a decrease in procedural success rate would not be well tolerated.

Safety and effectiveness of mechanical thrombectomy for acute ischemic stroke using single plane angiography

OBJECTIVES

Nearly all data on mechanical thrombectomy for acute ischemic stroke is based on procedures performed on biplane angiography systems. However, thrombectomy may be performed on single-plane systems in situations of triage or limited resources. We present the first US study comparing the safety and effectiveness of mechanical thrombectomy performed on single-plane vs. biplane systems.

METHODS AND METHODS

A retrospective review of a prospectively maintained database identified all patients treated with thrombectomy between July 2020 and July 2021 by a high-volume practice. Patients were dichotomized into those treated on single plane and biplane systems. Demographic, procedural, clinical and follow-up characteristics were compared.

RESULTS

Of the 246 patients treated with mechanical thrombectomy, 70 (33%) and 141 (66%) patients were treated on SP and BP systems, respectively. No significant differences were detected in follow-up 'good functional outcome' (mRS ≤ 2; SP 51% vs BP 43%, p = 0.14), successful recanalization (SP 87% vs BP 88%, p = 0.72), intra-procedural vascular injury (SP 3% vs BP 2%, p = 0.96), or time from groin puncture to reperfusion (SP 24 min vs BP 26 min, p = 0.58). Additionally, no significant differences were detected in peri-procedural complications, fluoroscopy times or total radiation. Patients treated on single plane systems required significantly more contrast.

CONCLUSIONS

Mechanical thrombectomy for acute ischemic stroke performed on single plane angiography systems is as safe and efficacious as when performed on biplane systems. Our results may have implications for increasing stroke care access, both domestically in underserved/rural areas and internationally when considering requirements for stroke care in lower-income countries.

Impact of monoplane to biplane angiography upgrade on diagnostic angiography procedures: A retrospective cross-sectional study

The radiation dose during digital subtraction angiography (DSA) examination is determined on the basis of many factors. The aim of this study was to evaluate the dose-area product, air kerma, and fluoroscopy time on monoplane and biplane DSA of the cerebral arteries. Our results show that biplane angiography offered lower DAP, cumulative air kerma at the reference point and fluoroscopy time despite comparable procedure time.. Further research in this area and personnel training warrant the improvement of the radiosafety of angiographic interventional procedures and further development of angiographic technology.

Telerobotic neurovascular interventions with magnetic manipulation

Advances in robotic technology have been adopted in various subspecialties of both open and minimally invasive surgery, offering benefits such as enhanced surgical precision and accuracy with reduced fatigue of the surgeon. Despite the advantages, robotic applications to endovascular neurosurgery have remained largely unexplored because of technical challenges such as the miniaturization of robotic devices that can reach the complex and tortuous vasculature of the brain. Although some commercial systems enable robotic manipulation of conventional guidewires for coronary and peripheral vascular interventions, they remain unsuited for neurovascular applications because of the considerably smaller and more tortuous anatomy of cerebral arteries. Here, we present a teleoperated robotic neurointerventional platform based on magnetic manipulation. Our system consists of a magnetically controlled guidewire, a robot arm with an actuating magnet to steer the guidewire, a set of motorized linear drives to advance or retract the guidewire and a microcatheter, and a remote-control console to operate the system under real-time fluoroscopy. We demonstrate our system's capability to navigate narrow and winding pathways both in vitro with realistic neurovascular phantoms representing the human anatomy and in vivo in the porcine brachial artery with accentuated tortuosity for preclinical evaluation. We further demonstrate telerobotically assisted therapeutic procedures including coil embolization and clot retrieval thrombectomy for treating cerebral aneurysms and ischemic stroke, respectively. Our system could enable safer and quicker access to hard-to-reach lesions while minimizing the radiation exposure to physicians and open the possibility of remote procedural services to address challenges in current stroke systems of care.

Occlusion Type, Number of Recanalization Passages and Dose Program Determine Radiation Dose in Endovascular Stroke Thrombectomy

PURPOSE

Identification of independent treatment factors associated with high radiation exposure during endovascular mechanical thrombectomy (EMT) in acute ischemic stroke.

METHODS

This retrospective analysis included all patients treated by means of EMT during the 2‑year period 2017-2018 in a comprehensive stroke center. The EMT were performed by four internal and three external certified neuroradiologists in a clinic overlapping on call system. Radiation exposure as the dependent variable (dose area product DAP, Gy ⋅ cm²) was dichotomized in < 100 Gy ⋅ cm² and ≥ 100 Gy ⋅ cm². Independent variables were age (< 75 years vs. ≥ 75 years), time of intervention (during vs. beyond workday), treating neuroradiologist (internal vs. external), occlusion type ("mono" vs. "tandem"), reperfusion success (TICI 0-2A vs. TICI 2B/3), recanalization attempts (≤ 2 vs. > 2) and dose protocol (normal dose in 2017 vs. low dose in 2018).

RESULTS

The EMT treatment of 208 patients (111 female, 97 male, mean age 71.6 years) was analyzed. Median DAP was 86.6 Gy ⋅ cm² and could be reduced from 104.8 Gy ⋅ cm² (N = 105 in 2017) to 73.3 Gy ⋅ cm² (N = 103 in 2018) with LD program. Univariable and multivariable binary logistic regression analysis revealed a significantly increased radiation exposure (≥ 100 Gy ⋅ cm²) in tandem occlusion type (P < 0.001), > 2 recanalization attempts (P < 0.001) and normal dose protocol (P = 0.002).

CONCLUSION

Low dose programs can significantly reduce the radiation exposure in EMT. High radiation exposure is significantly associated with more than two recanalization attempts and in cases of tandem occlusions.

The Feasibility of Mechanical Thrombectomy on Single-Plane Angiosuite: An In-Depth Analysis of Procedure Time

INTRODUCTION

Mechanical thrombectomy (MT) is usually performed on biplane (BP) angiosuites. When the BP angiosuite is not available, the single-plane (SP) angiosuite may be a substitute. However, the feasibility of MT performed on the SP angiosuite is yet to be elucidated. Therefore, we investigated the alternative effect of the SP angiosuite on the detailed division of procedure time, recanalization rate, and outcome in patients with anterior circulation infarction.

METHODS

The subjects included 80 consecutive patients with anterior circulation infarction who underwent MT at our hospital between May 2015 and December 2020. Demographics and characteristics of the BP and SP groups were assessed and compared. The time from puncture to guiding catheter placement (P-G), time from guiding catheter placement to recanalization (G-R), and time from puncture to recanalization (P-R) were also extracted. A good outcome was defined as a modified Rankin scale score ≤2 at 3 months.

RESULTS

Of the 80 patients, 67 and 13 were treated with BP and SP angiosuites, respectively. There were no differences in age, sex, complications, Alberta Stroke Program Early CT Score, National Institutes of Health Stroke Scale score at onset, occlusion site, rate of recombinant tissue-type plasminogen activator administration, stroke subtype, recanalization rate, and complications between the 2 groups. The rate of a good outcome was not different between the 2 groups. P-G was significantly longer in the SP group than in the BP group, whereas there was no significant difference in G-R and P-R between the 2 groups (P-G: BP 29.9 ± 21.8 vs. SP 48.5 ± 43.6 min, p = 0.04).

CONCLUSION

MT performed on the SP angiosuite tended to prolong the time for guiding catheter placement. However, there was no difference in the overall procedure time, recanalization rate, or outcome between BP and SP angiosuites. Therefore, if the BP angiosuite is not available, the use of the SP angiosuite should be encouraged.

Analysis of 565 thrombectomies for anterior circulation stroke: A Brazilian registry

INTRODUCTION

The benefits of mechanical thrombectomy in the treatment of patients with acute stroke due to large vessel occlusions (LVOs) have been extensively demonstrated by randomized trials and registries in developed countries. However, data on thrombectomy outside controlled trials are scarce in developing countries. The aim of this study was to assess the safety and efficacy, and to investigate the predictors for good and poor outcomes of thrombectomy for treatment of AIS due to anterior circulation LVOs in Brazil.

MATERIALS AND METHODS

This was a single center registry of thrombectomy in the treatment of stroke caused by anterior circulation LVOs. Between 2011 and 2019, a total of 565 patients were included.

RESULTS

the mean baseline NIHSS score on admission was 17.2. The average baseline ASPECTS was 8, and 91.0% of patients scored ≥6. Half of the patients received intravenous thrombolysis. The mean time from symptom onset to arterial puncture was 296.4 minutes. The mean procedure time was 61.4 minutes. The rates of the main outcomes were recanalization (TICI 2b-3) 85.6%, symptomatic intracranial hemorrhage (sICH) 8,1%, good clinical outcome (mRS=0-2) 43,5%, and mortality 22.1% at three months.

CONCLUSIONS

This study demonstrates the efficacy and safety of mechanical thrombectomy for treatment of patients with AIS of the anterior circulation in real-life conditions under limited facilities and resources. The results of the present study were relatively similar to those of large trials and population registers of developed countries.

Radiation exposure in endovascular stroke treatment of acute basilar artery occlusions-a matched-pair analysis

Abstract

Purpose

To determine the radiation exposure in endovascular stroke treatment (EST) of acute basilar artery occlusions (BAO) and compare it with radiation exposure of EST for embolic middle cerebral artery occlusions (MCAO).

Methods

In this retrospective analysis of an institutional review board−approved prospective stroke database of a comprehensive stroke center, we focused on radiation exposure (as per dose area product in Gy × cm², median (IQR)), procedure time, and fluoroscopy time (in minutes, median [IQR]) in patients receiving EST for BAO. Patients who received EST for BAO were matched case by case with patients who received EST for MCAO according to number of thrombectomy attempts, target vessel reperfusion result, and thrombectomy technique.

Results

Overall 180 patients (n = 90 in each group) were included in this analysis. General anesthesia was conducted more often during EST of BAO (BAO: 75 (83.3%); MCAO: 18 (31.1%), p < 0.001). Procedure time (BAO: 31 (20–43); MCAO: 27 (18–38); p value 0.226) and fluoroscopy time (BAO: 29 (20–59); MCAO: 29 (17–49), p value 0.317) were comparable. Radiation exposure was significantly higher in patients receiving EST for BAO (BAO: 123.4 (78.7–204.2); MCAO: 94.3 (65.5–163.7), p value 0.046), which represents an increase by 23.7%.

Conclusion

Endovascular stroke treatment of basilar artery occlusions is associated with a higher radiation exposure compared with treatment of middle cerebral artery occlusions.