Pere Canals

All Publications

• Deep learning-based model for difficult transfemoral access prediction compared with human assessment in stroke thrombectomy. Journal of neurointerventional surgery Canals, P., Garcia-Tornel, A., Requena, M., Jabłońska, M., Li, J., Balocco, S., Díaz, O., Tomasello, A., Ribo, M. 2025

  Abstract

  In mechanical thrombectomy (MT), extracranial vascular tortuosity is among the main determinants of procedure duration and success. Currently, no rapid and reliable method exists to identify the anatomical features precluding fast and stable access to the cervical vessels.A retrospective sample of 513 patients were included in this study. Patients underwent first-line transfemoral MT following anterior circulation large vessel occlusion stroke. Difficult transfemoral access (DTFA) was defined as impossible common carotid catheterization or time from groin puncture to first carotid angiogram >30 min. A machine learning model based on 29 anatomical features automatically extracted from head-and-neck computed tomography angiography (CTA) was developed to predict DTFA. Three experienced raters independently assessed the likelihood of DTFA on a reduced cohort of 116 cases using a Likert scale as benchmark for the model, using preprocedural CTA as well as automatic 3D vascular segmentation separately.Among the study population, 11.5% of procedures (59/513) presented DTFA. Six different features from the aortic, supra-aortic, and cervical regions were included in the model. Cross-validation resulted in an area under the receiver operating characteristic (AUROC) curve of 0.76 (95% CI 0.75 to 0.76) for DTFA prediction, with high sensitivity for impossible access identification (0.90, 95% CI 0.81 to 0.94). The model outperformed human assessment in the reduced cohort [F1-score (95% CI) by experts with CTA: 0.43 (0.37 to 0.50); experts with 3D segmentation: 0.50 (0.46 to 0.54); and model: 0.70 (0.65 to 0.75)].A fully automatic model for DTFA prediction was developed and validated. The presented method improved expert assessment of difficult access prediction in stroke MT. Derived information could be used to guide decisions regarding arterial access for MT.

  View details for DOI 10.1136/jnis-2024-021718

  View details for PubMedID 38702182

• Impact on collateral flow of devices used for endovascular treatment of stroke: an in-vitro flow model. Journal of neurointerventional surgery Requena, M., Li, J., Tiberi, R., Canals, P., Olive Gadea, M., de Dios Lascuevas, M., Jabłońska, M., Cendrero, J., Garcia-Tornel, A., Tomasello, A., Ribo, M. 2024; 16 (10): 1042-1045

  Abstract

  Collateral blood supply of distal vessels has been linked to clinical outcome, infarct volume and recanalization rates in patients with large vessel occlusion. Our study aimed to explore the effects of catheterization during mechanical thrombectomy in collaterals.We quantified the flow diversion effect secondary to arterial occlusions in an in vitro model which was connected in a flow-loop setup with a saline reservoir and a pump supplying pulsatile flow. Clot analogs were embolized to the middle cerebral artery (MCA) M1 or M2 segments. We used the same model with a clamped anterior communicating artery (AComA) to simulate its absence. An ultrasound flow sensor was placed at the vessel of interest. Flow rates and pressures were evaluated according to the following catheter locations: baseline (1) before and (2) after the occlusion; (3) 8F guiding catheter at the internal carotid artery (ICA) bulb; (4) at the cavernous segment; (5) at the cavernous segment a 0.071" distal access catheter at proximal M1; (6) 8F balloon guide catheter inflated.Collateral blood flow measured at distal anterior cerebral artery (ACA) (M1-MCA occlusion) and M2-MCA (M2-MCA occlusion) was progressively reduced as catheters were advanced through the ICA and MCA. In the lacking AComA model, the flow was further diminished as compared with the model with a patent AComA.Our in vitro study showed a progressive reduction of collateral blood flow due to the advance of catheters during mechanical thrombectomy.

  View details for DOI 10.1136/jnis-2023-020602

  View details for PubMedID 37648434

• Double stent-retriever as the first-line approach in mechanical thrombectomy: a randomized in vitro evaluation. Journal of neurointerventional surgery Li, J., Tiberi, R., Canals, P., Vargas, D., Castaño, O., Molina, M., Tomasello, A., Ribo, M. 2023; 15 (12): 1224-1228

  Abstract

  A repeated number of passes during mechanical thrombectomy leads to worse clinical outcomes in acute ischemic stroke. Initial experiences with the simultaneous double stent-retriever (double-SR) technique as the first-line treatment showed promising safety and efficacy results.To characterize the potential benefits of using the double-SR as first-line technique as compared with the traditional single-SR approach.Three types of clot analogs (soft, moderately stiff, and stiff) were used to create terminal internal carotid artery (T-ICA=44) and middle cerebral artery (MCA=88) occlusions in an in vitro neurovascular model. Sixty-six cases were randomized into each treatment arm: single-SR or double-SR, in combination with a 0.071" distal aspiration catheter. A total of 132 in vitro thrombectomies were performed. Primary endpoints were the rate of first-pass recanalization (%FPR) and procedural-related distal emboli.FPR was achieved in 42% of the cases. Overall, double-SR achieved a significantly higher %FPR than single-SR (52% vs 33%, P=0.035). Both techniques showed similar %FPR in T-ICA occlusions (single vs double: 23% vs 27%, P=0.728). Double-SR significantly outperformed single-SR in MCA occlusions (63% vs 38%, P=0.019), most notably in saddle occlusions (64% vs 14%, P=0.011), although no significant differences were found in single-branch occlusions (64% vs 50%, P=0.275). Double-SR reduced the maximal size of the clot fragments migrating distally (Feret diameter=1.08±0.65 mm vs 2.05±1.14 mm, P=0.038).This randomized in vitro evaluation demonstrates that the front-line double-SR technique is more effective than single-SR in achieving FPR when treating MCA bifurcation occlusions that present saddle thrombus.

  View details for DOI 10.1136/jnis-2022-019887

  View details for PubMedID 36627194

• Partial (SAVE) versus Complete (Solumbra) Stent Retriever Retraction Technique for Mechanical Thrombectomy: A Randomized In Vitro Study. AJNR. American journal of neuroradiology Jablonska, M., Li, J., Tiberi, R., Canals, P., Ortega, S., Tomasello, A., Ribo, M. 2023; 44 (10): 1165-1170

  Abstract

  Mechanical thrombectomy has become a first-line treatment for acute ischemic stroke. Several techniques combining stent retrievers and distal aspiration catheters have been described. We aimed to characterize the efficacy of 2 commonly used techniques according to clot characteristics.Soft (mean stiffness = 95.77 [SD, 5.80] kPa) or stiff (mean stiffness = 205.63 [SD, 6.70] kPa) clots (3 × 10 mm and 2 × 10 mm, respectively) were embolized to the distal M1 segment of the MCA in an in vitro model. The technique was randomly allocated (1:1): stent retriever assisted vacuum-locked extraction (SAVE) versus complete retraction (Solumbra). The primary end point was the percentage of first-pass recanalization. Secondary end points were periprocedural distal embolization measures.A total of 130 mechanical thrombectomies were performed (50 for soft clots and 15 for stiff clots per arm). Overall, the rate of first-pass recanalizaton was 35% with Solumbra and 15% with SAVE (P < .01). For stiff clots, the first-pass recanalizaton was equal for both methods (27%; P = 1.00). With soft clots, the first-pass recanalizaton was higher with Solumbra (38%) than with SAVE (12%; P < .01). When we used soft clots, the maximum embolus size (mean, 1.19 [SD, 0.9] mm versus 2.16 [SD, 1.48] mm; P < .01) and total area of emboli (mean, 1.82 [SD, 2.73] versus 3.34 [SD, 3.2]; P = .01) were also lower with Solumbra than with SAVE.Clot characteristics may influence the efficacy of the thrombectomy technique. In occlusions caused by soft clots, complete retrieval into the distal aspiration catheters achieved higher rates of first-pass recanalizaton and lower embolization.

  View details for DOI 10.3174/ajnr.A7996

  View details for PubMedID 37709355

  View details for PubMedCentralID PMC10549948

• Trackability of distal access catheters: an in vitro quantitative evaluation of navigation strategies. Journal of neurointerventional surgery Li, J., Tomasello, A., Requena, M., Canals, P., Tiberi, R., Galve, I., Engel, E., Kallmes, D. F., Castaño, O., Ribo, M. 2023; 15 (5): 496-501

  Abstract

  In mechanical thrombectomy (MT), distal access catheters (DACs) are tracked through the vascular anatomy to reach the occlusion site. The inability of DACs to reach the occlusion site has been reported as a predictor of unsuccessful recanalization. This study aims to provide insight into how to navigate devices through the vascular anatomy with minimal track forces, since higher forces may imply more risk of vascular injuries.We designed an experimental setup to monitor DAC track forces when navigating through an in vitro anatomical model. Experiments were recorded to study mechanical behaviors such as tension buildup against vessel walls, DAC buckling, and abrupt advancements. A multiple regression analysis was performed to predict track forces from the catheters' design specifications.DACs were successfully delivered to the target M1 in 60 of 63 in vitro experiments (95.2%). Compared to navigation with unsupported DAC, the concomitant coaxial use of a microcatheter/microguidewire and microcatheter/stent retriever anchoring significantly reduced the track forces by about 63% and 77%, respectively (p<0.01). The presence of the braid pattern in the reinforcement significantly reduced the track forces regardless of the technique used (p<0.05). Combined coil and braid reinforcement configuration, as compared with coil alone, and a thinner distal wall were predictors of lower track force when navigating with unsupported DAC.The use of microcatheter and stent retriever facilitate smooth navigation of DACs through the vascular tortuosity to reach the occlusion site, which in turn improves the reliability of tracking when positioning the DAC closer to the thrombus interface.

  View details for DOI 10.1136/neurintsurg-2022-018889

  View details for PubMedID 35450927

• A fully automatic method for vascular tortuosity feature extraction in the supra-aortic region: unraveling possibilities in stroke treatment planning. Computerized medical imaging and graphics : the official journal of the Computerized Medical Imaging Society Canals, P., Balocco, S., Díaz, O., Li, J., García-Tornel, A., Tomasello, A., Olivé-Gadea, M., Ribó, M. 2023; 104: 102170

  Abstract

  Vascular tortuosity of supra-aortic vessels is widely considered one of the main reasons for failure and delays in endovascular treatment of large vessel occlusion in patients with acute ischemic stroke. Characterization of tortuosity is a challenging task due to the lack of objective, robust and effective analysis tools. We present a fully automatic method for arterial segmentation, vessel labelling and tortuosity feature extraction applied to the supra-aortic region. A sample of 566 computed tomography angiography scans from acute ischemic stroke patients (aged 74.8 ± 12.9, 51.0% females) were used for training, validation and testing of a segmentation module based on a U-Net architecture (162 cases) and a vessel labelling module powered by a graph U-Net (566 cases). Successively, 30 cases were processed for testing of a tortuosity feature extraction module. Measurements obtained through automatic processing were compared to manual annotations from two observers for a thorough validation of the method. The proposed feature extraction method presented similar performance to the inter-rater variability observed in the measurement of 33 geometrical and morphological features of the arterial anatomy in the supra-aortic region. This system will contribute to the development of more complex models to advance the treatment of stroke by adding immediate automation, objectivity, repeatability and robustness to the vascular tortuosity characterization of patients.

  View details for DOI 10.1016/j.compmedimag.2022.102170

  View details for PubMedID 36634467

• A population synthesis fitting of the <i>Gaia</i> resolved white dwarf binary population within 100 pc MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY Torres, S., Canals, P., Jimenez-Esteban, F. M., Rebassa-Mansergas, A., Solano, E. 2022; 511 (4): 5462-5474

  View details for DOI 10.1093/mnras/stac374

  View details for Web of Science ID 000765919300007

• Catheter tip distensibility substantially influences the aspiration force of thrombectomy devices. Journal of neurointerventional surgery Li, J., Castaño, O., Tomasello, A., de Dios Lascuevas, M., Canals, P., Engel, E., Ribo, M. 2022; 14 (1)

  Abstract

  A direct aspiration first pass thrombectomy (ADAPT) is a fast-growing technique for which a broad catalog of catheters that provide a wide range of aspiration forces can be used. We aimed to characterize different catheters' aspiration performance on stiff clots in an in vitro vascular model. We hypothesized that labeled catheter inner diameter (labeled-ID) is not the only parameter that affects the aspiration force (asp-F) and that thrombus-catheter tip interaction and distensibility also play a major role.We designed an experimental setup consisting of a 3D-printed carotid artery immersed in a water deposit. We measured asp-F and distensibility of catheter tips when performing ADAPT on a stiff clot analog larger than catheter labeled-ID. Correlations between asp-F, catheter ID, and tip distensibility were statistically assessed.Experimental asp-F and catheter labeled-ID were correlated (r=0.9601; P<0.01). The relative difference between experimental and theoretical asp-F (obtained by the product of the tip's section area by the vacuum pressure) correlated with tip's distensibility (r=0.9050; P<0.01), evidencing that ADAPT performance is highly influenced by catheter tip shape-adaptability to the clot and that the effective ID (eff-ID) may differ from the labeled-ID specified by manufacturers. Eff-ID showed the highest correlation with experimental asp-F (r=0.9944; P<0.01), confirming that eff-ID rather than labeled-ID should be considered to better estimate the device efficiency.Catheter tip distensibility can induce a significant impact on ADAPT performance when retrieving a stiff clot larger than the device ID. Our findings might contribute to optimizing thrombectomy strategies and the design of novel aspiration catheters.

  View details for DOI 10.1136/neurintsurg-2021-017487

  View details for PubMedID 33858973

• The effects of unresolved double degenerates in the white dwarf luminosity function MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY Rebassa-Mansergas, A., Toonen, S., Torres, S., Canals, P. 2020; 491 (4): 5671-5681

  View details for DOI 10.1093/mnras/stz3371

  View details for Web of Science ID 000512310600081

• Oxygen-neon-rich merger during common envelope evolution MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY Canals, P., Torres, S., Soker, N. 2018; 480 (4): 4519-4525

  View details for DOI 10.1093/mnras/sty2121

  View details for Web of Science ID 000449617100020