scholarly journals Use of patient specific 3D printed neurovascular phantoms to simulate mechanical thrombectomy

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Kelsey N. Sommer ◽  
Mohammad Mahdi Shiraz Bhurwani ◽  
Vincent Tutino ◽  
Adnan Siddiqui ◽  
Jason Davies ◽  
...  

Abstract Background The ability of the patient specific 3D printed neurovascular phantoms to accurately replicate the anatomy and hemodynamics of the chronic neurovascular diseases has been demonstrated by many studies. Acute occurrences, however, may still require further development and investigation and therefore we studied acute ischemic stroke (AIS). The efficacy of endovascular procedures such as mechanical thrombectomy (MT) for the treatment of large vessel occlusion (LVO), can be improved by testing the performance of thrombectomy devices and techniques using patient specific 3D printed neurovascular models. Methods 3D printed phantoms were connected to a flow loop with physiologically relevant flow conditions, including input flow rate and fluid temperature. A simulated blood clot was introduced into the model and placed in the proximal Middle Cerebral Artery (MCA) region. Clot location, composition, length, and arterial angulation were varied and MTs were simulated using stent retrievers. Device placement relative to the clot and the outcome of the thrombectomy were recorded for each situation. Digital subtraction angiograms (DSA) were captured before and after LVO simulation. Recanalization outcome was evaluated using DSA as either ‘no recanalization’ or ‘recanalization’. Forty-two 3DP neurovascular phantom benchtop experiments were performed. Results Clot angulation within the MCA region had the most significant impact on the MT outcome, with a p-value of 0.016. Other factors such as clot location, clot composition, and clot length correlated weakly with the MT outcome. Conclusions This project allowed us to gain knowledge of how such characteristics influence thrombectomy success and can be used in making clinical decisions when planning the procedure and selecting specific thrombectomy tools and approaches.

2021 ◽  
Author(s):  
Kelsey Sommer ◽  
Mohammad Mahdi Shiraz Bhurwani ◽  
Vincent Tutino ◽  
Adnan Siddiqui ◽  
Jason Davies ◽  
...  

Abstract Background: The ability of the patient specific 3D printed neurovascular phantoms to accurately replicate the anatomy and hemodynamics of the chronic neurovascular diseases has been demonstrated by many studies. Acute occurrences, however, may still require further development and investigation and therefore we studied acute ischemic stroke (AIS). The efficacy of endovascular procedures such as mechanical thrombectomy (MT) for the treatment of large vessel occlusion (LVO), can be improved by testing the performance of thrombectomy devices and techniques using patient specific 3D printed neurovascular models.Methods: 3D printed phantoms were connected to a flow loop with physiologically relevant flow conditions, including input flow rate and fluid temperature. A simulated blood clot was introduced into the model and placed in the proximal Middle Cerebral Artery (MCA) region. Clot location, composition, length, and arterial angulation were varied and MTs were simulated using stent retrievers. Device placement relative to the clot and the outcome of the thrombectomy were recorded for each situation. Digital subtraction angiograms (DSA) were captured before and after LVO simulation. Recanalization outcome was evaluated using DSA as either ‘no recanalization’ or ‘recanalization’. Forty-two 3DP neurovascular phantom benchtop experiments were performed. Results: Clot angulation within the MCA region had the most significant impact on the MT outcome, with a p-value of 0.016. Other factors such as clot location, clot composition, and clot length correlated weakly with the MT outcome.Conclusions: This project allowed us to gain knowledge of how such characteristics influence thrombectomy success and can be used in making clinical decisions when planning the procedure and selecting specific thrombectomy tools and approaches.


2019 ◽  
Vol 11 (9) ◽  
pp. 931-936 ◽  
Author(s):  
Rose A Arslanian ◽  
Miklos Marosfoi ◽  
Jildaz Caroff ◽  
Robert M King ◽  
Christopher Raskett ◽  
...  

BackgroundEvidence is mounting that first-pass complete recanalization during mechanical thrombectomy is associated with better clinical outcomes in patients presenting with an emergent large vessel occlusion. We hypothesize that aspiration achieving complete clot ingestion results in higher first-pass successful recanalization with quantitative reduction in distal emboli.MethodsA patient-specific cerebrovascular replica was connected to a flow loop. Occlusion of the middle cerebral artery was achieved with clot analogs. Independent variables were the diameter of the aspiration catheter (0.054–0.088in) and aspiration pattern (static versus cyclical). Outcome measures were the first-pass rates of complete clot ingestion, the extent of recanalization, and the particle-size distribution of distal emboli.ResultsAll aspiration catheters were successfully navigated to the occlusion. Complete clot ingestion during aspiration thrombectomy resulted in first-pass complete recanalization in every experiment, only achieved in 21% of experiments with partial ingestion (P<0.0001). Aspiration through the large bore 0.088in device resulted in the highest rates of complete clot ingestion (90%). Cyclical aspiration (18–29 inHg, 0.5 Hz) significantly increased the rate of complete clot ingestion (OR21 [1.6, 266]; P=0.04). In all experiments, complete clot ingestion resulted in fewer and smaller distal emboli.ConclusionsComplete clot ingestion results in fewer distal emboli and the highest rates of first-pass complete recanalization. The rate of complete ingestion during aspiration thrombectomy is a function of both the inner diameter of the aspiration catheter and use of cyclical aspiration.


Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 658
Author(s):  
Piotr Piasecki ◽  
Marek Wierzbicki ◽  
Piotr Tulik ◽  
Katarzyna Potocka ◽  
Adam Stępień ◽  
...  

Background: The inadvertent detachment of stent retrievers during mechanical thrombectomy is an extremely rare but feared complication associated with poor clinical outcomes. We discuss management considerations after an unexpected disconnection of the pRESET stent retriever during mechanical thrombectomy, based on clinical experience and mechanical and phantom studies. Methods: We present a clinical course of rare accidents of stent-retriever separation inside an intracranial vessel that occurred in patients in a comprehensive stroke centre between 2018 and 2020. We designed a phantom study to assess the Tigertriever’s ability to remove a detached stent retriever from intercranial vessels. In the mechanical study, several types of stent retrievers were evaluated in order to find the weakest point at which detachment occurred. Results: Two patients (~0.7%) with inadvertent stent-retriever detachment were found in our database. Failed attempts of endovascular removal with no recanalization at the end of procedure were reported in both cases. mRS after 3 months was three and four respectively. In the mechanical study, the Tigertriever was the most resistant to detachment and was followed by Embotrap > pRESET > 3D Separator. In the phantom study, the pRESET device detached in a configuration resembling the M1 segment was successfully removed with the Tigertriever. Conclusions: Conservative management of the inadvertent detachment of stent retrievers during mechanical thrombectomy in large vessel occlusion may be acceptable in order to avoid further periprocedural complications after unsuccessful device removal attempts. Based on the phantom and mechanical studies, the Tigertriever may be a useful tool for the removal of detached pRESET devices.


2020 ◽  
pp. 1-8 ◽  
Author(s):  
Adithya S. Reddy ◽  
Yang Liu ◽  
Joshua Cockrum ◽  
Daniel Gebrezgiabhier ◽  
Evan Davis ◽  
...  

OBJECTIVEThe development of new endovascular technologies and techniques for mechanical thrombectomy in stroke has greatly relied on benchtop simulators. This paper presents an affordable, versatile, and realistic benchtop simulation model for stroke.METHODSA test bed for embolic occlusion of cerebrovascular arteries and mechanical thrombectomy was developed with 3D-printed and commercially available cerebrovascular phantoms, a customized hydraulic system to generate physiological flow rate and pressure, and 2 types of embolus analogs (elastic and fragment-prone) capable of causing embolic occlusions under physiological flow.RESULTSThe test bed was highly versatile and allowed realistic, radiation-free mechanical thrombectomy for stroke due to large-vessel occlusion with rapid exchange of geometries and phantom types. Of the transparent cerebrovascular phantoms tested, the 3D-printed phantom was the easiest to manufacture, the glass model offered the best visibility of the interaction between embolus and thrombectomy device, and the flexible model most accurately mimicked the endovascular system during device navigation. None of the phantoms modeled branches smaller than 1 mm or perforating arteries, and none underwent realistic deformation or luminal collapse from device manipulation or vacuum. The hydraulic system created physiological flow rate and pressure leading to iatrogenic embolization during thrombectomy in all phantoms. Embolus analogs with known fabrication technique, structure, and tensile strength were introduced and consistently occluded the middle cerebral artery bifurcation under physiological flow, and their interaction with the device was accurately visualized.CONCLUSIONSThe test bed presented in this study is a low-cost, comprehensive, realistic, and versatile platform that enabled high-quality analysis of embolus–device interaction in multiple cerebrovascular phantoms and embolus analogs.


2021 ◽  
Vol 12 ◽  
Author(s):  
Marion John Oliver ◽  
Emily Brereton ◽  
Muhib A. Khan ◽  
Alan Davis ◽  
Justin Singer

Objectives: Our primary objective was to determine the successful rate of recanalization of M1 large vessel occlusion using either the Trevo 4 × 30 mm or 6 × 25 mm stent during mechanical thrombectomy. Our secondary objectives were to determine differences between the use of these two stent retrievers regarding first-pass effect, periprocedural complications, and mortality in the first 90 days.Methods: This is a retrospective cohort study. Data regarding the stent used, recanalization, number of passes, periprocedural complications, and mortality were determined via our mechanical thrombectomy database along with chart review.Conclusion: When comparing Trevo 4 × 30 mm to 6 × 25 mm stent retrievers used in mechanical thrombectomy for middle cerebral artery large-vessel occlusion causing stroke, there is no statistically significant difference in successful recanalization rates, first-pass effect, perioperative complications, or mortality at 90 days. Studies like this will hopefully lead to further prospective, randomized controlled trials that will help show experts in the field an additional way to perform this procedure effectively and safely.


2018 ◽  
Vol 128 (5) ◽  
pp. 1349-1353 ◽  
Author(s):  
Roberto Crosa ◽  
Alejandro M. Spiotta ◽  
Matías Negrotto ◽  
Alejandra Jaume ◽  
Walter Casagrande

Long-awaited positive trial data have shown the efficacy of endovascular treatment in patients with ischemic stroke who arrive at the hospital within the first 6 hours with large-vessel occlusion of the anterior circulation. With the introduction of stent retrievers (SRs) for mechanical thrombectomy, efficient and safe large-artery recanalization treatment can be achieved. However, sometimes there are patients who do not attain complete flow restoration following attempts with traditional maneuvers. The authors present the case of a 57-year-old man with acute ischemic stroke due to an M1 embolus that extended into both M2 trunks. This patient was successfully treated with an innovative technique in which a Solitaire SR (Covidien) and a Catch SR (Balt) were used in a “Y” configuration, for which the authors coined the term “Y-stent retriever.”


2021 ◽  
Vol 39 (6_suppl) ◽  
pp. 363-363
Author(s):  
E. Reilly Scott ◽  
Samuel Morano ◽  
Andrea Quinn ◽  
Erica Mann ◽  
Michelle Ho ◽  
...  

363 Background: 3D printing is a growing tool in surgical education due to the ability to visualize organs, tissue, and masses from multiple angles before operating on a patient. Previous studies using highly detailed and expensive 3D models costing between $1,000-250 per model have been shown to enhance patient and trainee comprehension of tumor characteristics, goals of surgery, and planned surgical procedure for partial nephrectomies. In our study we aim to use simpler and less expensive models in a greater range of patients receiving partial nephrectomies to determine the use of 3D models in patient, resident, and fellow education. Methods: 3D models of the effected kidney, mass, renal artery, and renal vein were created using preoperative imaging of undergoing partial nephrectomies at Thomas Jefferson University Hospital (TJUH) costing $35 per model. Residents and fellows filled out 3 surveys assessing their surgical plan and their confidence in the chosen plan at 3 time points: 1) Before seeing the model, 2) After seeing the model before surgery, and 3) After surgery. Ten patients filled out 2 surveys about their understanding of the kidney, their disease, the surgery they will undergo, and the risks involved with surgery before and after seeing the model. Results: Based on surveys to assess for surgical plan and confidence given to resident and fellow surgeons before and after seeing the 3D model, confidence significantly increased. Surveys given after surgery assessing anatomic and surgical comprehension found that resident and fellow surgeons rated the helpfulness of the models on their anatomical comprehension 7.6 out of 10 and the help of the models on their surgical confidence 7 out of 10. Patient understanding of their kidney, disease, and surgery significantly increased after seeing the 3D model, but the risks associated with surgery did not significantly increase. The extent that the model helped the patients learn about the kidney, their disease, the surgery, and the risks related to surgery were rated an average of 8.33, 9.67, 9.5, and 8.83 out of 10, respectively. Conclusions: Patient-specific 3D models for partial nephrectomies increase resident and fellow confidence in surgical approach and helped patients learn about their disease and feel comfortable going into surgery. Thus, it is important to continue to explore 3D models as an educational tool for both trainees and patients and potentially include 3D models as part of the standard of care. Further research could continue to explore the utility of 3D models as a pre-operative educational tool for both patients and trainees in other surgical fields.


2018 ◽  
Vol 7 (6) ◽  
pp. 327-333 ◽  
Author(s):  
Mohamed S. Teleb

Background: Treatment of large vessel occlusion acute ischemic stroke with mechanical thrombectomy has become the standard of care after recent clinical trials. However, the degree of recanalization with stent retrievers remains very important in overall outcomes. We sought to review the utility of a new balloon guide catheter (BGC) in improving the degree of recanalization in conjunction with mechanical thrombectomy. Methods: The medical records of a prospectively collected endovascular ischemic stroke database were reviewed. All consecutive strokes when a FlowGate BGC was used with a thrombectomy stent retriever were identified. Use of a FlowGate BGC, number of passes, final Thrombolysis in Cerebral Infarction (TICI) score, trackability, and use of adjunct devices were all collected and analyzed. Results: Use of a FlowGate BGC resulted in 64% (33/52) first-pass effect (FPE) of TICI 2b/3, and specifically 46% (24/52) TICI 3 FPE (true FPE). A total of 52/62 (84%) of thrombectomy cases were treated with BGCs. In the remaining 10, the BGC was not inflated or used due to the clot not being visualized or the lesions being distal and BGC use thus not deemed appropriate. Adjunct use of an aspiration catheter was seen in 12% (6/52) of cases. The overall success with FlowGate BGCs with one or more passes of TICI 2b/3 was 94% (49/52). Trackability was achieved in 92% (57/62) of cases. Conclusions: Use of the FlowGate BGC as an adjunct to mechanical thrombectomy was associated with good FPE and an overall recanalization of TICI 2b/3 of 94%.


2021 ◽  
pp. 1357633X2098273
Author(s):  
Eyad Almallouhi ◽  
Ellen Debenham ◽  
Cheryl Grant ◽  
Alejandro M Spiotta ◽  
Christine A Holmstedt ◽  
...  

Introduction Clinical trials have proven the efficacy of mechanical thrombectomy in stroke patients with large-vessel occlusion presenting within 24 hours of symptom onset. Extending the thrombectomy window to 24 hours resulted in a higher number of thrombectomies being performed. However, little is known about the impact of the extended thrombectomy window on the telestroke call burden. Methods We used the prospectively maintained database of a telestroke network covering a large geographic area in the Southeast USA. We included patients presenting between January 2015 and December 2019. We compared the characteristics and outcomes between patients who presented before and after the publication of the extended window thrombectomy trials. Results A total of 9041 patients presented with stroke-like symptoms during the study period. Of these, 4995 presented after February 2018. There was no difference in the patient demographics in both groups. However, patients in the post extended window group had a lower National Institute of Health Stroke Scale on presentation (3 vs. 4; p < 0.001) and longer symptom-onset-to-door time (124 vs. 85 minutes; p < 0.001). The number of consults per month nearly doubled (200 vs. 103; p < 0.001) in the extended thrombectomy window era. Similarly, the number of mechanical thrombectomies performed per month increased from four to seven since extending the thrombectomy window ( p < 0.001). Discussion The number of telestroke consults nearly doubled after the publication of the extended thrombectomy window trials, with an increase in the number of thrombectomies performed. These findings have important operational implications for hospitals implementing telestroke call coverage.


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