Proximal Flow Control Research Articles

Distal placement of balloon guide catheter facilitates stent-retriever mechanical thrombectomy for acute ischemic stroke in the anterior circulation.

Although balloon guide catheters (BGCs) have been demonstrated to improve recanalization and functional outcomes by enabling proximal flow control and forced aspiration during mechanical thrombectomy (MT), the significance of the BGC location has been overlooked. We evaluated the impact of BGC location during MT for anterior circulation acute ischemic stroke (AIS). Patients were divided into the proximal and distal BGC groups according to the BGC tip location relative to the lower margin of the C1 vertebral body. Endovascular and clinical outcomes were compared between the two groups, including subgroup analyses of the two types of extracranial internal carotid artery (ICA) anatomy, categorized based on cerebral angiography. A total of 124 patients were analyzed, with 62 each in the proximal and distal BGC placement groups. The distal BGC group had higher rates of first-pass recanalization (FPR) (38.7% vs. 17.7%, P = 0.009) and favorable outcomes (64.5% vs. 46.8%, P = 0.047) with shorter procedure time (47.5min vs. 65min, P = 0.001) and fewer distal embolization (3.2% vs. 12.9%, P = 0.048) than the proximal BGC group. FPR was also more frequently achieved in the distal BGC group of patients with tortuous ICA (37.0% vs. 12.5%, P = 0.029). Multivariate analysis showed that distal BGC placement was an independent predictor of FPR (odds ratio, 3.092; 95% confidence interval, 1.326-7.210; P = 0.009). Distal BGC placement facilitates MT for AIS in the anterior circulation. Therefore, we suggest distal BGC placement to maximize the effect of thrombectomy, even for tortuous extracranial ICA.

A multiscale computational framework to evaluate flow alterations during mechanical thrombectomy for treatment of ischaemic stroke.

The treatment of ischaemic stroke increasingly relies upon endovascular procedures known as mechanical thrombectomy (MT), which consists in capturing and removing the clot with a catheter-guided stent while at the same time applying external aspiration with the aim of reducing haemodynamic loads during retrieval. However, uniform consensus on procedural parameters such as the use of balloon guide catheters (BGC) to provide proximal flow control, or the position of the aspiration catheter is still lacking. Ultimately the decision is left to the clinician performing the operation, and it is difficult to predict how these treatment options might influence clinical outcome. In this study we present a multiscale computational framework to simulate MT procedures. The developed framework can provide quantitative assessment of clinically relevant quantities such as flow in the retrieval path and can be used to find the optimal procedural parameters that are most likely to result in a favorable clinical outcome. The results show the advantage of using BGC during MT and indicate small differences between positioning the aspiration catheter in proximal or distal locations. The framework has significant potential for future expansions and applications to other surgical treatments.

Carotid artery revascularization using the Walrus balloon guide catheter: safety and feasibility from a US multicenter experience

IntroductionThe Walrus balloon guide catheter (BGC) is a new generation of BGC, designed to eliminate conventional limitations during mechanical thrombectomy.ObjectiveTo report a multi-institutional experience using this BGC for proximal flow...

Maximizing the catheter-to-vessel size optimizes distal flow control resulting in improved revascularization in vitro for aspiration thrombectomy

BackgroundBalloon guide catheters (BGCs) achieve proximal flow control during thrombectomy but antegrade intracranial flow often persists via the Circle of Willis. Closely sizing an aspiration catheter to the target vessel...

A Comprehensive Analysis of Dural Arteriovenous Fistula Involving the Superior Sagittal Sinus: A Systematic Review.

To evaluate published papers concerning dural arteriovenous fistula involving the superior sagittal sinus (SSS dAVF) treated with endovascular intervention. A literature review was performed to identify studies reporting the clinical characteristics, vascular anatomy, endovascular techniques, embolic materials, angiographical result, and outcomes of SSS dAVF. The analysis consisted of 40 case reports or series, comprising a total of 51 cases of SSS dAVF treated with endovascular intervention. Clinical symptoms included hemorrhage (29.4%), infarction (17.6%), and seizure (7.8%). The arterial supply included the middle meningeal artery (MMA) (100%), superficial temporal artery (STA) (62.7%), and occipital artery (OA) (49.0%). Bilateral MMAs supplied in 78.4% of the cases. A pial arterial supply was observed in 21.6% of the cases. Stenosis or occlusion of the sinus was seen in 37.3% of the cases. The distribution of the Borden classification was as follows: I (7.8%), II (37.3%), and III (54.9%). The endovascular techniques were transvenous embolization (TVE) alone (11.8%), transarterial embolization (TAE) alone (74.5%), and a combination thereof (13.7%). The types of embolic materials for TAE were a coil (25.5%), n-butyl-2-cyanoacrylate (NBCA) (33.3%), and Onyx (45.1%). The arterial pedicles for TAE included MMA (86.3%), STA (17.6%), and OA (9.8%). Direct surgical exposure for the alternative endovascular access was performed to the SSS (5.9%), MMA (3.9%), STA (5.9%), and OA (3.9%). Sinus angioplasty with or without stenting was done in 9.8% of the cases. Balloon-assisted Onyx TAE was done with proximal flow control (7.8%), collateral devascularization (5.9%), and sinus protection (3.9%). Complete occlusion was achieved in 86.3% of the cases while the number of endovascular sessions varied among patients: single (74.5%), double (15.7%), and triple (9.8%). The rate of a postoperative modified Rankin Scale (mRS) score of 0-2 was 89.3%, with morbidity and mortality rates of 7.8% and 3.9%, respectively. Two patients died, possibly due to postoperative acute SSS occlusion. The current systematic review disclosed several specific results, namely, the angioarchitectures of the SSS dAVF, the relationship between classification and hemorrhagic presentation, the diversity of treatment techniques, the association between the complete occlusion rate and the SSS condition, and the difficulty of achieving curable occlusion in a single session. These findings underscore the need for the development of endovascular techniques and devices to treat this challenging lesion. Improvements in adjunctive endovascular procedures, such as balloon-assisted techniques for Onyx TAE, may help support to the safe and effective obliteration of SSS dAVF.

Role of Balloon Guide Catheter in Modern Endovascular Thrombectomy.

Proximal flow control achieved with a balloon guide catheter (BGC) during endovascular treatment of acute ischemic stroke is reviewed in this article. In clinical practice, BGCs offer a multi-faceted approach for clot retrieval by creating proximal flow arrest, reducing embolic burden, and shortening procedure time. Evaluation of frontline thrombectomy procedures with BGCs revealed advantages of combined use over the conventional guide catheter (CGC), notably in the significant reduction of distal emboli to both the affected and previously unaffected territories. Recently, new measures of early and complete reperfusion at first thrombectomy pass have been identified as independent predictors of improved outcomes, which were consistently demonstrated with use of BGC as a safe and effective option to minimize number of passes during intervention. Prior randomized controlled trials reported the positive correlation between BGC-treated patients and a lower risk of mortality as well as shortened procedure time. While BGC use is more common in stent retriever-mediated mechanical thrombectomy, preliminary data has shown the potential benefit of device application during contact aspiration thrombectomy to achieve successful recanalization. However, the question of which major endovascular strategy reigns superior as a frontline remains to be answered. Along with clinical case assessments, BGC performance during in-vitro simulation was analyzed to further understand mechanisms for optimization of thrombectomy technique.

Impact of Balloon-Guiding Catheter Location on Recanalization in Patients with Acute Stroke Treated by Mechanical Thrombectomy.

Mechanical thrombectomy with proximal flow control and forced aspiration may improve the outcome of endovascular revascularization therapy for patients with acute stroke. The purpose of this study was to compare the impact of balloon-guiding catheter locations in patients treated for anterior circulation acute ischemic stroke using mechanical thrombectomy. The influence of the balloon-guiding catheter location (proximal, balloon-guiding catheter tip proximal to C1 vertebral body; distal, between the skull base and the C1 vertebral body) was analyzed in patients with acute anterior circulation stroke treated with stent-retriever thrombectomy. The baseline angiographic/clinical characteristics, time intervals, recanalization rates, and clinical outcomes were compared. The clinical analysis included 102 patients (mean age, 69.5 ± 12.8 years; male/female ratio = 52:50). The balloon-guiding catheter was located distally in 49 patients and proximally in 53 patients for flow control and forced aspiration during stent retrieval. The puncture-to-recanalization time was shorter in the distal group than in the proximal group (40 versus 56 minutes, P = .02). Successful and complete recanalizations were more frequently achieved in the distal group compared with the proximal group (98.0% versus 75.5%. P = .003; 67.3% versus 45.3%, P = .04, respectively). Multivariate analysis showed that the distal catheterization location was independently associated with successful recanalization (adjusted OR, 13.4; 95% CI, 2.4-254.8; P = .02). Location of the balloon-guiding catheter has a significant impact on recanalization in patients with acute stroke. The balloon-guiding catheter should be positioned as distally as safely possible in the cervical ICA for maximally effective thrombectomy.

Carotid artery stenting with proximal embolic protection via the transbrachial approach: sheathless navigation of a 9-F balloon-guiding catheter.

Transbrachial carotid artery stenting (TB-CAS) is performed as an alternative procedure for patients with hostile vascular anatomy of the aortic arch and aortic or peripheral artery disease. Proximal protection during TB-CAS is not generally feasible because a small size of the brachial artery may preclude using a large-diameter sheath introducer. We, herein present a novel method that enables proximal protection during TB-CAS by sheathless navigation of a 9-F balloon-guiding catheter equivalent to a 7-F sheath. We analyzed eight consecutive patients who underwent TB-CAS with proximal protection using the sheathless method from April 2016 to June 2017. Relevant demographic, radiographic, and procedural features were retrospectively reviewed. We performed TB-CAS using our method for five patients with a bovine or type 3 aortic arch, for one patient with combined peripheral artery disease, and for two patients with a type 1 or 2 aortic arch. We successfully navigated the balloon-guiding catheter via the brachial artery and performed CAS under proximal flow control in all patients. However, we experienced kinking and exchange of the balloon-guiding catheter in one patient and a periprocedural thromboembolic event occurred. A pseudoaneurysm at the access site developed in one patient. TB-CAS with proximal embolic protection using the sheathless method is feasible and may provide an alternative approach in carefully selected patients who have difficult anatomy in the transfemoral approach and plaques with a high risk of distal embolization.

Efficacy of the proximal balloon flow control method for endovascular coil embolisation as a novel adjunctive technique: A retrospective analysis.

Background and purpose In our previous study, we established the utility of 8-F balloon guide catheters for anterior circulation aneurysms. This study aims to assess the efficacy of the proximal flow control method using 8-F balloon guide catheters for coil deployment into the aneurysms as a novel adjunctive technique for aneurysmal coil embolisation along with local balloon neck remodeling, stent assist and double catheter techniques. Materials and methods We retrospectively analysed patients who underwent endovascular coiling of anterior circulation aneurysms between August 2013 and December 2017. Results Of 206 patients enrolled in this study, the balloon of the guiding catheter was inflated to assist coil deployment in 43 patients (20.9%). In addition, the proximal flow control method found utility in cases with small aneurysms and relatively narrow-necked internal carotid artery. We observed no intraprocedural complications in this study. Conclusion This technique enabled secure coil deployment without navigating another microcatheter or balloon catheter around the aneurysms.

Abstract TP28: Influence of Ballon Guide Catheter Cathterization on Mechanical Thrombectomy in Acute Stroke Patients

Background and purpose: Mechanical thrombectomy (MT) with proximal flow control and negative aspiration may improve the outcome of endovascular revascularization therapy (ERT) for acute stroke patients. The purpose of this study is to compare the effects of balloon guide catheter (BGC) catheterization on benchtop tests and in patients treated for anterior circulation acute ischemic stroke using mechanical thrombectomy. Method: A benchtop test was performed with a silicone cerebrovascular model. The negative suction pressure was compared according to the catheterization location {proximal; placement of BGC proximal to atlas vertebral body(2nd, 3rd and 4th cervical vertabra) , distal; Placement of BGC is the skull base or upper side of atlas vertebral body lower margin}of the BGC. The influences of the BGC was analyzed in acute stroke patients with large anterior circulation occlusion. The baseline clinical characteristics, procedural variables, recanalization rate and clinical outcomes were compared. Result: The benchtop test showed that the distally located balloon showed 11 % increase in suction pressure. The clinical analysis included 104 patients (age: 70.1±12.3 70). The locations of the BGC inflations were distal (n=47) and proximal (n=57) groups. Proximal BGC group was more frequently associated with hypertension (77% versus 57%; P=0.031). The recanalization rate was significantly higher in the distal BGC group (95.7% versus 66.7%; P <0.0001). Needle to recanalization time is more shorter in distal balloon group than proximal balloon group (48.57 ± 26.1 VS 68.3 ± 44.8 P = 0.005). The incidence of emboli to new territory (ENT) was less frequent in the distal BGC group. Conclusions: Catheterization of the BGC may have influences on the recanalization of occluded anterior circulation arteries in acute stroke patients. The BGC should be navigated as distally as possible in the cervical ICA for maximally effective thrombectomy.

8-F balloon guide catheter for embolization of anterior circulation aneurysms: an institutional experience in 152 patients.

ABSTRACTThe use of 8-F balloon guide catheter (BGC) for proximal flow control was previously shown to prevent distal embolic complications during mechanical clot retrieval in patients with acute ischemic stroke. In this retrospective study, the utility of 8-F BGCs for proximal flow control during endovascular coiling of anterior circulation aneurysms was investigated. Patients who underwent endovascular coiling for anterior circulation aneurysms between August 2013 and December 2016 were retrospectively analyzed. Among a total of 152 patients included in this series, 64 patients presented with aneurysmal rupture, whereas the aneurysms were detected incidentally or due to mass effects in the remaining patients. 8-F BGCs were successfully navigated in all patients. The balloon was inflated during navigation in 19 patients. Inflation of the catheter balloon during coil embolization was required in 34 patients; this was performed as an emergency maneuver in six of these patients. Thromboembolic complications occurred in one patient. 8-F BGC can be effectively used for proximal flow control during endovascular treatment of anterior circulation aneurysms. The other advantages included improved navigation of tortuous arterial anatomy, coil stabilization during aneurysmal coiling, and freedom to utilize aneurysmal neck-remodeling balloons for additional adjunctive techniques or to deploy rescue stents. This novel approach might be safely and effectively used in patients undergoing endovascular treatment for anterior circulation aneurysms.

Balloon-assisted Catheterization Technique under Proximal Flow Control with Balloon Guiding Catheter in Endovascular Treatment of Cerebral Aneurysm

Balloon-assisted Catheterization Technique under Proximal Flow Control with Balloon Guiding Catheter in Endovascular Treatment of Cerebral Aneurysm

Proximal Flow Control with a Balloon during the Treatment of Left Subclavian Artery Aneurysms.

Proximal Flow Control with a Balloon during the Treatment of Left Subclavian Artery Aneurysms.

Safe time duration for temporary middle cerebral artery occlusion in aneurysm surgery based on motor-evoked potential monitoring.

Background:Temporary vessel occlusion of the parent artery is an essential technique for aneurysm surgery. Our aim was to clarify the safe time for temporary occlusion for aneurysm surgery, that is the “safe time duration” (STD), in which brain tissue exposed to ischemia will almost never fall into even the ischemic penumbra during temporary occlusion of the middle cerebral artery (MCA), and even transient postoperative motor impairment will be rare using intraoperative motor-evoked potentials (MEP).Methods:Twenty-four patients underwent MCA aneurysm clipping surgery with MEP monitoring for 13 ruptured aneurysms and 11 unruptured aneurysms. The duration of vessel occlusion in patients without MEP changes was measured as the STD. Average STD was calculated as 95% confidence interval for the population mean using sample data from patients with MEP changes and patients without changes.Results:All 24 patients received proximal flow control only. Five patients (20.8%) developed significant intraoperative MEP changes. Time to MEP change (i.e., STD) in these patients was 4.6 ± 2.1 min. In patients without MEP changes, STD was 2.7 ± 1.4 min. Average STD was thus 3.1 ± 0.7 min.Conclusions:The 95% lower confidence limit for average STD was 2.4 min when applying temporary occlusion on the proximal side of the MCA. This STD resembled that previously reported for temporary proximal occlusion of the internal carotid artery.

O-033 Aspiration Efficacy of Suction Catheter in the Management of Distal Embolization During Interventional Treatment of Acute Ischemic Stroke

IntroductionImproved recanalization rate and immediate flow restoration have been achieved by the latest clot retrieval (thrombectomy) systems in the acute ischemic stroke treatment. However, clot debris generated during mechanical thrombectomy...

Abstract W P16: Quantitative Analysis of Distal Emboli During Mechanical Thrombectomy With Stent-Trievers

Introduction: While the use of stentrievers has been shown to improve clinical outcomes compared with previous generation technology in the interventional treatment of stroke, there remains variability in clinical results. One contributor may be distal clot fragmentation during thrombectomy. Our goal is to assess various treatment strategies that can reduce the risk of distal embolization. Materials and Methods: Three different treatment strategies using stentrievers (Solitaire FR) included 1 Proximal flow control with a balloon guide catheter (BGC), 2 Thromboaspiration via a 5Fr distal access catheter (DAC) in the origin of the MCA, and 3 Thrombectomy through a conventional 6Fr conventional guide catheter (CGC). The vascular phantom included collateral circulation via PCom and ACom arteries and two different clot types were used( Stroke 2013;44:1396) . For each strategy and clot type, 8 replicate experiments were performed. Large clot fragments (>1000μm) were separated from the effluent collected at each the ACA and MCA outlets and the longest dimension recorded. Particle size and number (<1000μm) were measured with a Coulter counter. A cumulative distribution of clot fragments was made with a moving average of 10μm-wide bins centered at 0.2μm intervals across a range of 25-1000μm. Exponential decay functions were fit to the data and time-constants were calculated. Results: For visible fragments, >1mm, both the use of the BGC and the DAC techniques produce fewer visible clot fragments (>1000μm) as compared to CGC technique (p<0.05, hard clot). For particulate sizes between 250-1000μm there was a trend towards a lower rate of hard clot embolic particulate with the DAC technique. In the size range of 25-250μm, the BGC produced less clot fragments than the DAC technique (p<0.05, hard clot). In the <25 μm group the BGC technique produced a lower rate of embolic particulates compared to the DAC or CGC technique (p<0.05). All regressions had a coefficient of determination >0.95. The BGC and DAC methods were found to have the shortest time-constants for hard and soft clots, respectively. Conclusion: Use of the BGC during a Solitaire FR thrombectomy is associated with statistically lower rates of distal emboli across a broad range of embolic particle sizes..

Preliminary study on safe thresholds for temporary internal carotid artery occlusion in aneurysm surgery based on motor-evoked potential monitoring.

Background:The study aims were to clarify safe duration for temporary vessel occlusion of the internal carotid artery (ICA) during aneurysm surgery as exactly as possible. We examined safe time duration (STD), where brain tissue exposed to ischemia will never fall into even the ischemic penumbra using intraoperative motor-evoked potential (MEP).Methods:In 45 patients, temporary occlusion of the ICA was performed with MEP. We measured STD as the duration of temporary vessel occlusion during which MEP changes did not occur. To estimate average STD, we calculated the 95% confidence interval for the population mean from sample data for STD in patients with MEP changes and in patients without changes.Results:In the proximal-control group, 4 of 38 patients (10.5%) developed intraoperative MEP changes. In 4 patients, the time to MEP change (i.e. STD) was 6.0 ± 2.5 min. STD was 3.8 ± 1.6 min in the 34 patients without changes. The average STD was 4.0 ± 0.6 min. In the trap group (proximal and distal flow control), five of seven patients (60.0%) experienced intraoperative MEP changes (STD, 2.3 ± 1.0 min). All patients in the trap group who developed MEP changes showed involvement of the anterior choroidal artery (AchA) in the trapped segment. Average STD was 2.3 ± 1.1 min when trapping involving the AchA.Conclusions:Although the study is preliminary based on the limited number of the patients, the 95% upper confidence limit for average STD was 4.6 min when the ICA was occluded proximal to the aneurysm, 3.4 min when the ICA was trapped involving the AchA.

Reduction in Distal Emboli With Proximal Flow Control During Mechanical Thrombectomy

To evaluate the impact of proximal flow control on efficacy and safety of mechanical thrombectomy in an in vitro middle cerebral artery occlusion. Three independent variables, including clot type, device (Merci Retriever, Solitaire FR, and Trevo devices), and use of a balloon guide catheter, were used to ascertain the impact of proximal flow control on the size and number of distal emboli generated during thrombectomy. Secondary end points were the recanalization rate and amount of flow restored. Use of the balloon guide catheter during thrombectomy of the fragile, hard clot significantly reduced the formation of large distal emboli with a diameter >1 mm, regardless of the device used (P<0.01). Applying aspiration via the balloon guide catheter in place of the conventional guide catheter resulted in a significant increase of flow reversal (P<0.0001). Prior to thrombectomy, deployment of the stent-trievers produced immediate flow restoration through the soft and hard clot occlusions, 69.2 ± 27.3 and 45.5 ± 22.8 mL/min, respectively, that was preserved after the balloon inflation because of collateral flow via the posterior communication artery. After deployment but before thrombectomy, no flow was restored when using the Merci Retriever. After thrombectomy, complete flow restoration was achieved in a majority of cases. The Merci Retriever required more thrombectomy attempts to achieve hard clot removal compared with the stent-trievers when the conventional guide catheter was used (1.5 versus 1.1). The risk of distal embolization was significantly reduced with the use of the balloon guide catheter.

Significance of Combining Distal Filter Protection and a Guiding Catheter With Temporary Balloon Occlusion for Carotid Artery Stenting: Clinical Results and Evaluation of Debris Capture

Carotid artery stenting (CAS) with distal filter protection allows for continuous cerebral perfusion. However, this procedure has been reported to be associated with a greater risk of debris migrating into the cerebral arteries. To improve the extent of debris capture, we used a guiding catheter with temporary balloon occlusion and temporary aspiration from the common carotid artery. Eighty-one stenoses were treated with CAS using distal filter protection; simple distal filter protection (conventional group, n = 50) or distal filter protection with temporary proximal flow control and blood aspiration was performed using a 9-F guiding catheter with a temporary balloon occlusion positioned at the common carotid artery (proximal occlusion group, n = 31). Clinical outcomes, rates of capturing visible debris, and new ischemic signals on diffusion-weighted magnetic resonance imaging (DWI) were evaluated. Events involving procedure-related emboli causing neurological deficits occurred in 6.0% (3/50) and 3.2% (1/31) of patients in the conventional and proximal occlusion groups, respectively (P = 1.0). The rates of visible debris capture by using the distal filter were 64.0% (32/50) and 29.0% (9/31) in the convention and proximal occlusion groups, respectively, being significantly lower in the proximal occlusion group (P < 0.01). New ischemic signals on DWI were detected in 44.0% (22/50) and 12.9% (4/31) of cases in the conventional and proximal occlusion groups, respectively, being significantly lower in the proximal occlusion group (P < 0.01). Combining distal filter protection and a guiding catheter with temporary balloon occlusion in CAS significantly reduced visible debris captured by the distal filter and occurrence of small postprocedural cerebral infarctions detected by DWI.

O-017 Reduction in distal emboli with proximal flow control during mechanical thrombectomy: a quantitative in vitro study

PurposeThe hypothesis is that proximal flow control with a balloon guide catheter (BGC) in the cervical internal carotid artery (ICA) during mechanical thrombectomy will reduce the amount of distal emboli.Materials...