THINGS TO KNOW ABOUT SUPPORT CATHETER
What is a support catheter?
The Suggested new guide catheter features a plurality of wires, which are contained within the lumen of the catheter, extending from the proximal end of the catheter until its tip. Exit openings lead the wires outside the catheter lumen for a defined distance. Near the distal end of the catheter, the wires re-enter the catheter, and are Securely anchored at or within the catheter wall. 5 15 25 35 40 45 50 55 60 65 2 A Second Segment of exposure of the wires to the exterior of the catheter is located at its proximal portion, the catheter Segment which is not inserted into the patient's vascular System, and which is manipulated by the operator. Small knobs on the outside of the catheter are connected to the wires at the proximal Segment of the catheter.
These Small knobs connected to the wires allow the operator to advance and retract them, leading to their flexing away from (with advancing movements of the wires) or their repositioning adjacent to the body of the catheter (with retracting move ments of the wires) at a defined section near its distal end. The bending out of the wire forms Supporting loops, which firmly anchor the distal portion within the aortic root. The knobs located at the proximal portion of the wires allow for their being locked in any position. Adjustment of the degree of extension or retraction of the wires, and thus the size of the distal wire loops, allows for a safe and Secure engage ment of the distal opening of the catheter within the coronary ostium targeted.
Where do we use support catheters?
Case examplesCase illustration 1: Improved microcatheter support for microcatheter manipulations in PED deployment A 56-year-old patient (patient 3) with a remote history of microsurgical clipping of two right middle cerebral artery (MCA) bifurcation aneurysms in the setting of subarachnoid hemorrhage presented with new right facial droop secondary to Bell’s palsy. Subsequent evaluation revealed recurrence of the previously clipped aneurysms, a new 20 mm right cavernous ICA aneurysm and a new 6 mm fusiform left M2 segment aneurysm. Considering the large size of the right ICA aneurysm, this was treated first using the PED. Follow-up angiography 6 months after PED treatment of the ICA aneurysm demonstrated expected flow remodeling of the ICA aneurysm with marked decrease in the aneurysm pouch. However, there was interval growth of the fusiform left M2 aneurysm to 8 mm. Given the fusiform nature of the left M2 aneurysm and the patient’s need for continued dual antiplatelet therapy, a decision was made to treat the enlarging M2 aneurysm with the PED.
The PED embolization was performed as previously described.9 A triaxial system through right common femoral artery access was built with a 90 cm 6 F 0.087 inch ID sheath, a 115 cm 5 F 0.058 inch ID Navien catheter and a 150 cm 0.027 inch ID microcatheter. The smaller 5 F OD (compared with the 5.2 F DAC and 6 F proximally) allowed superior intraprocedure roadmaps through the sheath (). It was tracked smoothly over the with a 2 standard 0.014 inch microwire to its final position in the mid left M1 segment. This ultra-distal positioning of the Navien catheter in the M1 allowed one-to-one tactile feedback during the pushing/pulling microcatheter manipulations needed for PED deployment. A 3 mm×18 mm PED was successfully implanted across the aneurysm neck despite multiple vessel turns traversed to reach the target landing zone. No complications occurred during the procedure and final control angiography demonstrated patency of the parent vessels without evidence of vasospasm or dissection.
Case illustration 2: Ease of stent delivery and improved microcatheter stability during aneurysm access through stent tines in stent-assisted aneurysm embolization A 50-year-old patient (patient 5) with a long-standing history of headaches and cardiopulmonary disease presented with episodic dizziness and non-invasive imaging suggestive of a basilar apex aneurysm. Diagnostic cerebral angiography revealed a 4 mm wide-necked left SCA aneurysm (figure 4A), a 6 mm right MCA bifurcation aneurysm and a 5 mm left MCA bifurcation aneurysm.
Considering both MCA aneurysms were irregular and wide-necked, the therapeutic plan was to first microsurgically clip the MCA aneurysms sequentially, then treat the SCA aneurysm 6 weeks after the last craniotomy with single-stage stent-assisted coiling. One week before embolization the patient was pretreated with oral aspirin 325 mg and clopidogrel 75 mg daily. The procedure was performed under general endotracheal anesthesia. The right common femoral artery was accessed with a 5 F short sheath (Terumo Medical Corporation) and then exchanged for a 6 F 55 cm sheath (Cook Medical) placed in the mid descending aorta. The left subclavian artery was selected with a 5 F JB-1 glide catheter and the sheath was advanced over the JB-1 into the left subclavian artery, proximal to the left vertebral artery origin.
The JB-1 and glidewire were removed. A 115 cm 5 F Navien was then coaxially introduced with a 150 cm Marksman microcatheter. Under roadmap guidance, the Marksman was advanced over a Synchro 2 standard 0.014 inch microwire into the distal left vertebral artery, then into the basilar artery and the right posterior cerebral artery (PCA). The Navien catheter was tracked over the Marksman into its final position in the proximal to mid basilar junction (figure 4B,C). The Marksman and microwire were removed. A 150 cm XT27 microcatheter (Stryker) was advanced through the Navien catheter past the aneurysm into the left PCA. A 3 mm×20 mm Neuroform EZ stent (Stryker) was advanced through the XT27 microcathteter and deployed across the aneurysm neck. Despite tortuosity of the left vertebral artery, the Neuroform EZ stent was easily maneuvered and deployed from the left P1 to the mid basilar artery.
Of note, as the stent was deployed and slack removed from the system, the Navien catheter migrated slightly forward (figure 4D). The XT27 microcatheter and stent delivery wire were then removed. A SL-10 microcatheter (Stryker) was advanced through the Navien catheter over a Synchro 2 standard microwire into the basilar artery and the left SCA aneurysm was accessed through the stent tines without any forward jump of the microwire. Coil embolization proceeded with Target 360 Ultra coils (Stryker), 2 mm×6 cm followed by 1 mm×3 cm (figure 4E). The SL-10 microcatheter was extremely stable during the coiling with little catheter kickback. No complications occurred during the procedure. Final control angiography demonstrated patency of the parent vessels without evidence of vasospasm or dissection
How do support cathters work?
In 11 intracranial interventions, either a 6 F 0.072 inch ID or 5 F 0.058 inch ID was positioned beyond the clinoidal ICA or V3 segment. Details of these procedures are presented in table 1. The mean patient age was 52.8 years (range 41–67). There were eight women and three men in this series. Figures 1 and 2 demonstrate the parent vessel tortuosity for each of these patients. The Navien was tracked into position using a 0.027 inch microcatheter in all but one case (patient 10) in whom the 0.027 inch Headway microcatheter in jailing of the coiling microcatheter. Of the 11 interventions, three were located along the anterior circulation and were all PED treatments of wide-necked aneurysms. In one of these cases, two aneurysms were treated.
The aneurysms were in the following locations: posterior communicating artery, ICA termination, A2–A3 junction and M2. For these three anterior circulation PED embolizations, the 5 F 0.058 inch ID was used in conjunction with a 90 cm 6 F positioned in the proximal cervical ICA providing a triaxial support system. PED embolization procedures were performed as previously described.9 The final intraprocedural position was in the middle of the M1 segment for one case and the distal supraclinoid ICA for the other two.
The remaining eight interventions involved the posterior circulation for the following treatments: single-stage stent coiling of superior cerebellar artery (SCA) aneurysm (n=2), single-stage stent coiling of basilar apex aneurysm (n=1), single-stage Y stent coiling of basilar apex aneurysm (n=2), liquid embolization of arteriovenous malformations (AVM; n=2) and coil-assisted PED treatment of posterior inferior cerebellar artery (PICA) aneurysm (n=1). In these cases the Navien served as the primary guide catheter within either a 5 F or 6 F long sheath (≥55 cm) positioned in the subclavian artery proximal to the vertebral artery origin.
Typically, the proximal vertebral artery was first selected with a 5 F JB-1 glide catheter. The JB-1 catheter was then exchanged for the Navien. Thereafter, the Navien was tracked over a 0.027 inch microcatheter into its final ultra-distal location. Of the eight posterior circulation cases, the 5 F Navien was used in six cases with the following final intraprocedural positions: distal V4 (n=3), proximal basilar (n=1), proximal to mid basilar (n=1) and mid basilar (n=1). The 6 F 0.072 inch ID Navien was used in the other two posterior circulation interventions.
For one of these cases the 6 F Navien was positioned in the V3–V4 junction to allow jailing of the coiling microcatheter during PED coiling of a PICA aneurysm. For the other embolization, the 6 F was positioned in the V3–V4 junction for added stability in single-stage Y-stent coiling (with jailing) of a small wide-necked basilar apex aneurysm. No complications (eg, dissection) were encountered during positioning. All but one intervention was completed successfully. The one incomplete case was a small choroidal AVM where no definitive large arterial feeders were identified with microcatheter angiography. For this reason, embolization was not possible.
What does the scientific literature say about support cathters?
The retrograde SFA access technique was a sheathless approach in 15 (30%) cases with insertion of a support catheter or balloon over a 0.018-inch wire. A 4-F sheath was inserted in 32 (64%) cases and a 6-F sheath in 3 (6%). In 13 (26%) cases, the ‘‘double-balloon’’ technique was required for successful wire passage. In 3 of the TEA cases with resultant flush SFA occlusion, successful wire passage into the CFA was achieved only by using the catheter from a retrograde approach. Guidewire passage was successful in 48 (96%) procedures; the 2 (4%) failures were secondary to extensive calcification in one and a flush SFA occlusion after TEA in the other; a re-entry device had not been used but might have been successful.
The treatment applied after successful wire passage was standard balloon angioplasty (6%), drug-eluting balloons (16%), atherectomy (2%), nitinol stents (80%), and stent-graft implantation (2%). Hemostasis at the distal puncture site was achieved in 30 cases through external compression only; in 16 cases additional balloon tamponade of the puncture site was performed. In 2 cases, the distal puncture site had severe arteriosclerotic disease, and deployment of a nitinol stent across the puncture area was pre-planned, leading to an immediate seal of the distal access. In 2 cases, a vascular closure was used to effectively seal the access point via a 6-F sheath from the retrograde access. Mean hemostasis time was 9.2 minutes (range 3–30). Duplex ultrasound on the first post-intervention day demonstrated 2 pseudoaneurysms at the ipsilateral proximal femoral access site and 2 at the distal retrograde access site. In all of these cases, a 4-F sheath had been used.
One proximal femoral pseudoaneurysm required surgical repair, while the others were successfully managed using ultrasound-assisted compression. In both distal pseudoaneurysms, the sheath had not been removed during the intervention but after the patient was transferred from the angiography suite. One small arteriovenous fistula at the distal puncture site occurred; however, it required no treatment. There was an episode of peripheral embolization that was successfully treated with aspiration thrombectomy. No other adverse events occurred during or within the 30 days following the procedure.
WHat are the advantages of using support cathters?
The treatment of chronic total occlusions (“CTOs') has raised even further challenges to accessing both sides of the CTO. A CTO is a chronic problem that developed into a total obstruction or blockage in a vessel. The composition of a CTO may be classified as hard plaque, soft plaque or a mix ture of the two. Percutaneous intervention is a minimally invasive way to treat vessels having CTOS and is accom plished with conventional guidewire techniques, e.g., slowly advancing the guidewire through the CTO to obtain the 10 15 25 30 35 40 45 50 55 60 65 2 desired access to deploy balloon, stents, or other medical devices. As set forth above, catheters often are used to provide Support to the guidewire. In many cases, there is a cap with a calcified lesion at the proximal side of the occlusion (the “proximal cap’), where the blood flow is obstructed at the occlusion. It can be very difficult to advance a guidewire through this proximal cap to penetrate the CTO unless one can maneuver a guidewire or device through it. There are micro channels that run through the CTO. These micro channels may aid the medical profes sional in being able to maneuver a guidewire through a CTO. Crossing the proximal cap with a guidewire or other device or exploiting the micro channels, is a goal in recanalizing a vessel since it facilitates clearing the occlusion from the ves sel. It would be advantageous to have a Support catheter that has the properties of flexibility and rigidity that further aid in maneuvering a guidewire through the CTO. More particu larly, it would be advantageous to have a Support catheter that can track to the site of a vessel occlusion, Such as a CTO, and provide Sufficient Support to aid the guidewire to cross the occlusion.