Safety and efficacy of the sonographic acceleration of the middle cerebral artery recanalization: results of the pilot thrombotripsy study

Sonolysis in risk reduction of symptomatic and silent brain infarctions during coronary stenting (SONOREDUCE): Randomized, controlled trial

BACKGROUND

Silent brain infarcts can be detected on magnetic resonance imaging (MRI) in ~22% of patients after coronary angioplasty and stenting (CS). The effect of periprocedural sonolysis on the risk of new brain infarcts during CS was examined.

METHODS

Patients undergoing elective CS were allocated randomly to a bilateral sonolysis group (70 patients, 58 men; mean age, 59.9 years) or a control group (74 patients, 45 men; mean age, 65.5 years). Neurologic examination, cognitive function tests, and brain MRI were performed prior to intervention and at 24 h after CS. Neurologic examination and cognitive function tests were repeated at 30 days after CS.

RESULTS

No significant differences were observed in the number of patients with new infarcts (25.7 vs. 18.9%, P = 0.423), the number of lesions (1.3 ± 1.0 vs. 2.9 ± 5.3, P = 0.493), lesion volume (0.16 ± 0.34 vs. 0.28 ± 0.60 mL, P = 0.143), and the number of patients with new ischemic lesions in the insonated MCA territories (18.6vs. 17.6%, P = 0.958) between the sonolysis group and the control group. There were no cases of stroke, transient ischemic attack, myocardial infarction, or death in the two groups. Intracranial bleeding was reported only in 1 patient in the control group (0 vs. 1.4%, P = 0.888). Clock-drawing test scores at 30 days were significantly higher in the sonolysis group than in the control group (median 3.0 vs. 2.5, P = 0.031).

CONCLUSIONS

Sonolysis does not reduce the risk of new brain infarcts after CS. The effect of sonolysis on number and volume of ischemic lesions and cognitive function should be assessed in further studies.

SONOlysis in prevention of Brain InfaRctions During Internal carotid Endarterectomy (SONOBIRDIE) trial - study protocol for a randomized controlled trial

BACKGROUND

Carotid endarterectomy (CEA) is a beneficial procedure for selected patients with an internal carotid artery (ICA) stenosis. Surgical risk of CEA varies from between 2 and 15%. The aim of the study is to demonstrate the safety and effectiveness of sonolysis (continual transcranial Doppler monitoring, TCD) using a 2-MHz diagnostic probe with maximal diagnostic energy on the reduction of the incidence of stroke, transient ischemic attack (TIA) and brain infarction detected using magnetic resonance imaging (MRI) by the activation of the endogenous fibrinolytic system during CEA.

METHODS/DESIGN

Design: a multicenter, randomized, double-blind, sham-controlled trial.

SCOPE

international, multicenter trial for patients with at least 70% symptomatic or asymptomatic ICA stenosis undergoing CEA.

INCLUSION CRITERIA

patients with symptomatic or asymptomatic ICA stenosis of at least 70% are candidates for CEA; a sufficient temporal bone window for TCD; aged 40-85 years, functionally independent; provision of signed informed consent. Randomization: consecutive patients will be assigned to the sonolysis or control (sham procedure) group by computer-generated 1:1 randomization. Prestudy calculations showed that a minimum of 704 patients in each group is needed to reach a significant difference with an alpha value of 0.05 (two-tailed) and a beta value of 0.8 assuming that 10% would be lost to follow-up or refuse to participate in the study (estimated 39 endpoints).

ENDPOINTS

the primary endpoint is the incidence of stroke or TIA during 30 days after CEA and the incidence of new ischemic lesions on brain MRI performed 24 h after CEA in the sonolysis and control groups. Secondary endpoints are occurrence of death, any stroke, or myocardial infarction within 30 days, changes in cognitive functions 1 year post procedure related to pretreatment scores, and number of new lesions and occurrence of new lesions ≥0.5 mL on post-procedural brain MRI.

ANALYSIS

descriptive statistics and linear/logistic multiple regression models will be performed. Clinical relevance will be measured as relative risk reduction, absolute risk reduction and the number needed to treat.

DISCUSSION

Reduction of the periprocedural complications of CEA using sonolysis as a widely available and cheap method may significantly increase the safety of CEA and extend the indication criteria for CEA.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02398734 . Registered on 20 March 2015.

Sonolysis in Prevention of Brain Infarction During Cardiac Surgery (SONORESCUE): Randomized, Controlled Trial

Here, we examined whether intraoperative sonolysis can alter the risk of new ischemic lesions in the insonated brain artery territory during coronary artery bypass grafting (CABG) or valve surgery.Silent brain ischemic lesions could be detected in as many as two-thirds of patients after CABG or valve surgery.Patients indicated for CABG or valve surgery were allocated randomly to sonolysis (60 patients, 37 males; mean age, 65.3 years) of the right middle cerebral artery (MCA) during cardiac surgery and control group (60 patients, 37 males; mean age, 65.3 years). Neurologic examination, cognitive function tests, and brain magnetic resonance imaging (MRI) were conducted before intervention as well as 24 to 72 hours and 30 days after surgery.New ischemic lesions on control diffusion-weighted MRI in the insonated MCA territory ≥0.5 mL were significantly less frequent in the sonolysis group than in the control group (13.3% vs 26.7%, P = 0.109). The sonolysis group exhibited significantly reduced median volume of new brain ischemic lesions (P = 0.026). Stenosis of the internal carotid artery ≥50% and smoking were independent predictors of new brain ischemic lesions ≥0.5 mL (odds ratio = 5.685 [1.272-25.409], P = 0.023 and 4.698 [1.092-20.208], P = 0.038, respectively). Stroke or transient ischemic attack occurred only in 2 control patients (P = 0.496). No significant differences were found in scores for postintervention cognitive tests (P > 0.05).This study provides class-II evidence that sonolysis during CABG or valve surgery reduces the risk of larger, new ischemic lesions in the brain.www.clinicaltrials.gov (NCT01591018).

Sonothrombolysis

Thrombo-occlusive disease is a leading cause of morbidity and mortality. In this chapter, the use of ultrasound to accelerate clot breakdown alone or in combination with thrombolytic drugs will be reported. Primary thrombus formation during cardiovascular disease and standard treatment methods will be discussed. Mechanisms for ultrasound enhancement of thrombolysis, including thermal heating, radiation force, and cavitation, will be reviewed. Finally, in-vitro, in-vivo and clinical evidence of enhanced thrombolytic efficacy with ultrasound will be presented and discussed.

Safety and efficacy of endovascular sonolysis using the EkoSonic endovascular system in patients with acute stroke

BACKGROUND AND PURPOSE

Sonolysis is a new therapeutic procedure for arterial recanalization. The aim of this study was to confirm the safety and efficacy of endovascular sonolysis by using the EkoSonic Endovascular System in subjects with acute ischemic stroke.

MATERIALS AND METHODS

Patients with acute ischemic stroke with occlusion of the middle cerebral artery or basilar artery were enrolled consecutively in this prospective study. The control group (44 MCA and 12 BA occlusions) was selected from historical controls. EkoSonic Endovascular System was started within 8 hours after stroke onset. The NIHSS score at hospital admission, after 24 hours, and at 7 days; arterial recanalization; early neurologic improvement; symptomatic intracerebral hemorrhage; and favorable 3-month clinical outcome defined as a modified Rankin Scale score of 0-2 were evaluated by statistical means.

RESULTS

Fourteen patients (10 men; mean age, 65.1 ± 11.2 years; median NIHSS score, 16.5) underwent EkoSonic endovascular sonolysis. Arterial recanalization after endovascular treatment was achieved in 6 of 7 (85.7%) patients with MCA occlusion (4 complete recanalizations) and in all 7 (100%) patients with BA occlusion (6 complete recanalizations). No (0%) symptomatic intracerebral hemorrhage or periprocedural complications occurred. Seven (50%) patients were independent at 3 months (median mRS score, 2). Early neurologic improvement and favorable clinical outcome were significantly more frequent in patients with MCA occlusion undergoing EkoSonic endovascular sonolysis than in controls (100% and 71.4% versus 4.6% and 13.6% of patients; P = .0001 and P = .003, respectively). Three-month mortality was significantly lower in patients with BA occlusion undergoing EkoSonic endovascular sonolysis than in controls (0% versus 66.7% patients, P = .013).

CONCLUSIONS

In this small study, EkoSonic endovascular sonolysis allowed safe and potentially effective revascularization in patients experiencing acute ischemic stroke.

The role of sonolysis and sonothrombolysis in acute ischemic stroke: a systematic review and meta-analysis of randomized controlled trials and case-control studies

OBJECTIVES

To assess the evidence on the safety and efficacy of sonothrombolysis in acute stroke.

SEARCH METHODS

Electronic databases and grey literature were searched under different MeSH terms from 1970 to present.

SELECTION CRITERIA

Randomized control trials (RCTs) and case control studies (CCSs) on sonolysis and sonothrombolysis alone or with microsphere in acute stroke patients (>18 old). Outcome measures included complete recanalization (CR) at 1-2 and 24 hours, 3 months modified Rankin Scale (mRS), and symptomatic intracerebral hemorrhage (sICH). Data was extracted to Review Manager software.

RESULTS

Fifty-seven studies were retrieved and analyzed. Ten studies (7 RCTs and 3 CCSs) were included in our meta-analysis, which revealed that sonolysis and sonothrombolysis are safe (OR of sICH: 1.14; 95% confidence interval (CI): 0.56- 2.34;P=0.71) and effective (OR of CR at 1-2 hours: 2.95;95% CI: 1.81-4.81;P<0.00001) and have more than two-fold higher likelihood of favourable long-term outcome (3-month mRS 0-2; OR: 2.20; CI:1.52-3.19;P<0.0001). Further subgroup analysis based on the presence of microsphere revealed that it is safe (OR of sICH: 1.18; CI:0.433.24;P=0.75) and effective (OR of CR: 2.61; CI: 1.36-4.99;P=0.004). Subgroup analysis based on sonolysis revealed to be safe and effective.

CONCLUSIONS

This novel treatment appears safe and effective. The evidence of microsphere as an enhancement of sonothrombolysis is evolving.

Safety and efficacy of sonothrombolysis using bilateral TCD monitoring by diagnostic 2 MHz probes - a pilot study

INTRODUCTION

Sonothrombolysis is a new treatment method for patients with acute ischemic stroke (IS). Various ultrasound frequencies and intensities are being tested these days. The aim of this pilot study was to assess the safety and efficacy of sonothrombolysis using 2 diagnostic probes and bilateral monitoring in patients with acute occlusion of the middle cerebral artery (MCA).

PATIENTS AND METHODS

Twelve consecutive IS patients (7 males; age 47 - 78, average 64.1 ± 9.4 years) with acute MCA occlusion and contraindication of thrombolysis were included in the study. 60-min bilateral 2-MHz pulsed-wave Doppler monitoring of the area of occlusion was performed in all patients (Group 1). The control group consisted of 37 IS patients (20 males; age 32 - 78, average 62.2 ± 12.1 years) treated with standard sonothrombolysis and selected from the Thrombotripsy Study database (Group 2). The differences in number of recanalized arteries after a 1 h treatment, independent patients (modified Rankin scale [mRS] value of 0 - 2) after 90 days and symptomatic intracerebral hemorrhages (SICH) were statistically evaluated.

RESULTS

Complete recanalization was found in 4 (30.0%) Group 1 and in 12 (32.4%) Group 2 patients. Seven (58.3%) Group 1 and 22 (59.5%) Group 2 patients were independent after 90 days. SICH was found in none of Group 1 patients and in 1 (2.7%) of the Group 2 patients (P>0.05 in all cases).

CONCLUSION

In this pilot study, sonothrombolysis using 2 probes and bilateral monitoring is safe but not more effective than standard sonothrombolysis in acute IS patients with MCA occlusion.

Changes in middle cerebral artery blood flow velocity during sonolysis using a diagnostic transcranial probe with a 2-MHz Doppler frequency in healthy volunteers

OBJECTIVES

Ultrasound has various biological effects in the human body. The effects of continuous monitoring with ultrasound (sonolysis) on vasodilatation of the radial artery were described recently. We wanted to ascertain whether similar changes in the blood flow velocity during sonolysis could also be detected in the middle cerebral artery.

METHODS

Fifteen healthy volunteers (6 male and 9 female; age range, 23-68 years; mean ± SD, 47.1 ± 15.1 years) were subjected to 1 hour of middle cerebral artery sonolysis using a diagnostic transcranial probe with a 2-MHz Doppler frequency and measurement of the blood flow velocity at 2-minute intervals. During a second session, a flow curve was recorded for 10 seconds at 2-minute intervals. The peak systolic velocity, end-diastolic velocity, mean flow velocity, pulsatility index, and resistive index were recorded during both measurements.

RESULTS

Irregular changes in the measured blood flow parameters were recorded during both sessions. Changes in particular hemodynamic parameters during both measurements were similar. The changes in the peak systolic velocity, end-diastolic velocity, mean flow velocity, pulsatility index, and resistive index were not significantly different between the two measurements (P < .05 in all cases).

CONCLUSIONS

As opposed to sonolysis of the radial artery, sonolysis of the middle cerebral artery using a diagnostic 2-MHz frequency in healthy volunteers did not lead to changes in the flow curve or peripheral vasodilatation.

Changes in blood flow velocity in the radial artery during 1-hour ultrasound monitoring with a 2-MHz transcranial probe--a pilot study

PURPOSE

Multiple biologic effects of ultrasound on the human body have been described. Our aim was to monitor changes in blood flow velocities in the radial artery during continuous pulsed wave Doppler monitoring (DM).

METHODS

Fifteen healthy volunteers (8 males; mean age 55 ± 17 years) underwent two 1-hour sessions of left radial artery DM using a diagnostic transcranial 2-MHz pulsed-wave transducer. Blood flow velocities were recorded twice at 2-minute intervals, for the measurement of peak systolic velocity, end-diastolic velocity, and mean flow velocity, and the calculation of pulsatility index, and resistance index. Insonation was either intermittent (by periods <10 seconds) or continuous during the first session, and conversely during the second session 2 weeks later.

RESULTS

Blood flow velocities and indices fluctuated during both sessions. These changes were symmetrical during the intermittent DM session. In contrast, end-diastolic velocity increased while pulsatility index and resistance index decreased significantly during the continuous DM session (p < 0.05 for all three parameters). The changes in peak systolic velocity and mean flow velocity did not differ between sessions.

CONCLUSIONS

One-hour sonographic Doppler monitoring using a 2-MHz diagnostic transcranial PW Doppler probe may induce peripheral vasorelaxation in humans.

Changes in hemocoagulation in acute stroke patients after one-hour sono-thrombolysis using a diagnostic probe

The aim was to monitor the changes in hemocoagulation parameters in acute ischemic stroke (AIS) patients after sono-thrombolysis of the occluded middle cerebral artery using a duplex transcranial probe with 2.0-MHz frequency in Doppler mode. Sixteen AIS patients indicated for intravenous thrombolysis (IVT) (8 males; mean age 68.3 +/- 7.1 y) and 16 AIS patients contraindicated for IVT (11 males; mean age 67.9 +/- 7.9 y) were randomized for sono-thrombolysis (8 + 8 patients) or standard treatment (control group) (8 + 8 patients). The significant decrease of plasminogen activator inhibitor-1, plasminogen and alpha-2-antiplasmin activity by a mean of 60, 32 and 24%, respectively, and the increase of tissue plasminogen activator by a mean of 56% was found after sono-thrombolysis when compared with control group (p < 0.0125); these changes were more evident in patients treated with a combination of sono-thrombolysis and IVT (79, 38, 50 and 82%, respectively) than in patients treated by sono-thrombolysis alone (34, 13, 17 and 30%, respectively).