A thrombectomy system, comprising: a delivery catheter configured to be advanced through vasculature of a patient to a thrombus site within a blood vessel; an aspiration catheter adapted to apply suction to an expandable aspiration funnel extending from a distal end of the aspiration catheter, the aspiration funnel comprising a first section and a second section adjacent to the first section, the second section providing a reduction of diameter, the aspiration funnel being configured to be movably disposed within the delivery catheter in a retracted position in a compressed state and at least partially outside the delivery catheter in an extended and expanded position, a diameter of a distal end of the aspiration funnel being greater in the extended and expanded position than in the retracted position; a clot-capture element configured to capture a thrombus and to be at least partially withdrawn with the captured thrombus into the aspiration funnel; and a microcatheter adapted to carry the clot-capture element to the thrombus site, wherein the aspiration funnel is formed by a mesh of at least two sets of helicoidal filaments turning respectively in opposite directions and being intertwined, the mesh of the first section having helicoidal filaments with a braiding angle configured to provide outward radial forces higher than in the second section; wherein the aspiration funnel comprises a non-permeable covering; wherein the aspiration funnel is configured to adapt its shape and length to an inner wall of the blood vessel such that the first section of the aspiration funnel becomes appositioned against the inner wall of the blood vessel to reduce blood flow through the blood vessel, and such that the aspiration funnel lengthens as it narrows to retain the thrombus within the aspiration funnel; wherein the clot-capture element is configured to be movably disposed within the microcatheter in a retracted position, and wherein the microcatheter is configured to be movably disposed within the aspiration catheter. a delivery catheter configured to be advanced through vasculature of a patient to a thrombus site within a blood vessel; an aspiration catheter adapted to apply suction to an expandable aspiration funnel extending from a distal end of the aspiration catheter, the aspiration funnel comprising a first section and a second section adjacent to the first section, the second section providing a reduction of diameter, the aspiration funnel being configured to be movably disposed within the delivery catheter in a retracted position in a compressed state and at least partially outside the delivery catheter in an extended and expanded position, a diameter of a distal end of the aspiration funnel being greater in the extended and expanded position than in the retracted position; a clot-capture element configured to capture a thrombus and to be at least partially withdrawn with the captured thrombus into the aspiration funnel; and a microcatheter adapted to carry the clot-capture element to the thrombus site, wherein the aspiration funnel is formed by a mesh of at least two sets of helicoidal filaments turning respectively in opposite directions and being intertwined, the mesh of the first section having helicoidal filaments with a braiding angle configured to provide outward radial forces higher than in the second section; wherein the aspiration funnel comprises a non-permeable covering; wherein the aspiration funnel is configured to adapt its shape and length to an inner wall of the blood vessel such that the first section of the aspiration funnel becomes appositioned against the inner wall of the blood vessel to reduce blood flow through the blood vessel, and such that the aspiration funnel lengthens as it narrows to retain the thrombus within the aspiration funnel; wherein the clot-capture element is configured to be movably disposed within the microcatheter in a retracted position, and wherein the microcatheter is configured to be movably disposed within the aspiration catheter.