IMAGING SYSTEM INCLUDES IMAGING PROBE AND DELIVERY DEVICES
An imaging system is provided comprising an imaging probe and at least one delivery device. The imaging probe comprises an elongate shaft, a rotatable optical core and an optical assembly. The elongate shaft comprises a proximal end, a distal portion, and a lumen extending between the proximal end and the distal portion. The rotatable optical core is positioned within the lumen of the elongate shaft and comprises a proximal end and a distal end. The rotatable optical core is configured to optically and mechanically connect with an interface unit. The optical assembly is positioned in the elongate shaft distal portion and proximate the rotatable optical core distal end. The optical assembly is configured to direct light to tissue and collect reflected light from the tissue. The imaging probe is constructed and arranged to collect image data from a patient site. The at least one delivery device is constructed and arranged to slidingly engage the imaging probe. Methods of introducing the imaging probe and the at least one delivery catheter into a patient are also provided.
1 . A method of performing intravascular imaging of a neurovascular blood vessel, the method comprising:
(a) advancing a guide catheter into a patient such that a distal portion of the guide catheter is positioned proximate a target site in the neurovasculature;
(b) advancing a microcatheter through the guide catheter;
(c) advancing an imaging probe through the microcatheter, such that the guide catheter, microcatheter, and imaging probe are arranged coaxially;
(d) delivering a flushing fluid comprising radiopaque contrast through (i) the guide catheter or (ii) an intermediate catheter disposed within the guide catheter such that the flushing fluid flows distally toward the target side around an outer surface of the microcatheter toward the target site to clear blood from an imaging field; and
(e) performing a pullback of the imaging probe while acquiring intravascular optical imaging data of the neurovascular blood vessel.
2 . The method of claim 1 , wherein the guide catheter comprises an inner diameter of between about 5 Fr and about 7 Fr.
3 . The method of claim 1 , wherein the guide catheter comprises an inner diameter of about 0.088″.
4 . The method of claim 1 , wherein the intermediate catheter comprises an inner diameter between about 0.053″ and about 0.070″.
5 . The method of claim 1 , wherein the microcatheter comprises an inner diameter between about 0.0165″ and about 0.027″.
6 . The method of claim 1 , wherein a distal portion of the imaging probe has an outer diameter less than about 0.020″.
7 . The method of claim 6 , wherein the distal portion of the imaging probe has an outer diameter between about 0.014″ and about 0.016″.
8 . The method of claim 1 , wherein the target site is selected from an internal carotid artery, a middle cerebral artery, a vertebral artery, and a basilar artery.
9 . The method of claim 1 , wherein a distal end of the microcatheter and/or intermediate catheter is positioned proximate to a location selected from the group consisting of: an internal carotid artery; an intracranial internal carotid artery; a petrous segment of the internal carotid artery; a proximal cavernous segment of the internal carotid artery; a proximal cavernous segment of the internal carotid artery; a distal cavernous/clinoidal segment of the carotid artery; a supraclinoid segment of the internal carotid artery; an M1 segment of a middle cerebral artery; a V3-V4 junction of a vertebral artery; a distal V4 segment; a proximal basilar artery segment; a proximal-to-mid basilar artery segment; or a mid-basilar artery segment.
10 . The method of claim 1 , wherein delivering the flushing fluid comprises delivering the flushing fluid at a flow rate between about 3 mL/second and about 6 mL/second.
11 . The method of claim 10 , wherein delivering the flushing fluid comprises delivering contrast at about 5 mL/second.
12 . The method of claim 10 , wherein delivering the flushing fluid comprises delivering contrast at about 4 mL/second.
13 . The method of claim 10 , wherein a total delivered volume during the delivering step is about 30 mL when delivered at 5 mL/second for 6 seconds or about 24 mL when delivered at 4 mL/second for 6 seconds.
14 . The method of claim 1 , further comprising delivering a bolus of 10 mL or less of contrast to facilitate fluoroscopic localization prior to the pullback.
15 . The method of claim 1 , wherein the flushing fluid is delivered through the guide catheter while the imaging probe is positioned in the microcatheter.
16 . The method of claim 1 , wherein the flushing fluid is delivered through the guide catheter into a space between the guide catheter and the intermediate catheter and/or into a space between the intermediate catheter and the microcatheter.
17 . The method of claim 1 , wherein the guide catheter and/or the intermediate catheter includes one or more sideholes configured to deliver the flushing fluid toward the target site during the pullback.
18 . The method of claim 1 , wherein performing the pullback comprises retracting the imaging probe at a rate between 5 mm/second and 60 mm/second over a distance between 10 mm and 150 mm while rotating an optical assembly of the imaging probe to acquire intravascular optical coherence tomography image data.
19 . The method of claim 18 , wherein performing the pullback comprises retracting the imaging probe at a rate of about 40 mm/second.
20 . The method of claim 18 , wherein performing the pullback comprises retracting the imaging probe over a distance of about 40 mm.
21 . The method of claim 1 , wherein initiation or rate of the pullback is determined based on lumen clearing during the delivering step.
22 . The method of claim 1 , wherein the flushing fluid comprises contrast mixed with saline.
23 . The method of claim 22 , wherein the flushing fluid comprises between 20% and 100% contrast mixed with saline.
24 . A method of performing intravascular imaging of a neurovascular blood vessel, the method comprising:
(a) advancing an intermediate catheter to a location proximate a target site in the neurovasculature;
(b) advancing a microcatheter through the intermediate catheter;
(c) advancing an imaging probe through the microcatheter such that the intermediate catheter, the microcatheter, and the imaging probe are arranged coaxially, and such that an optical assembly of the imaging probe is positioned proximate the target site;
(d) delivering a flushing fluid comprising radiopaque contrast through the intermediate catheter such that the flushing fluid flows distally toward the target site around an outer surface of the microcatheter to clear blood from a luminal segment surrounding the optical assembly; and
(e) performing a pullback of the imaging probe while acquiring intravascular optical imaging data of the neurovascular blood vessel.
25 . The method of claim 24 , wherein the intermediate catheter comprises an inner diameter between about 0.053″ and about 0.070″.
26 . The method of claim 24 , wherein the microcatheter comprises an inner diameter of about 0.021″.
27 . The method of claim 24 , wherein the intermediate catheter comprises an outer diameter of less than 7F.