Abstract 059: The Tenzing‐Dotter Technique for Endovascular Management of Atherosclerotic Cervical ICA Tandem Large Vessel Occlusions
Authors: English Joey D 
Published: March 2024

Introduction
The endovascular treatment of acute ischemic stroke due to atherosclerotic occlusion/near‐occlusion of the cervical internal carotid artery (ICA) and a concurrent intracranial large vessel occlusion (LVO) remains challenging, and the optimal approach remains unclear. Options include initial angioplasty and/or stenting of the cervical lesion followed by intracranial thrombectomy versus Dotter navigation of catheters through the cervical lesion to first target the intracranial LVO. We describe a novel Tenzing‐Dotter technique which utilizes a Tenzing device for the Dotter delivery of large bore (0.070”) and super‐large bore (0.088”) catheters through cervical atherosclerotic lesions to gain access to the intracranial circulation in tandem LVO patients.

Methods
We performed a retrospective review our single center experience of atherosclerotic tandem occlusion patients in which the Route 92 Medical Tenzing ® 7 (T7®) and Tenzing ® 8 (T8®) delivery catheters were used to Dotter‐deliver large bore or super‐large bore catheters, respectively, through the cervical ICA lesion to gain access to the intracranial circulation. We reviewed clinical, radiographic and procedural data to describe the safety and efficacy of this approach.

Results
Twenty patients were identified that that atherosclerotic occlusion/near‐occlusion of the cervical ICA and a single symptomatic intracranial LVO. The mean age was 65 (44 – 89), and 40% were female. The mean NIHSS was 14 (7‐25) and 40% were treated initially with intravenous thrombolytics. The ipsilateral cervical ICA was occluded in 11 of 20 patients (55%) and nearly‐occluded (degree of stenosis 90‐99%) in 9 of 20 patients (45%). The intracranial occlusions were carotid terminus (5), M1 middle cerebral artery (14) and M2 middle cerebral artery (1). Seven patients were treated with Tenzing 7 paired with a large bore catheter (6 with Medtronic React 71 and 1 with Route 92 Medical Hipoint 70), while 13 were treated with Tenzing 8 paired with a super‐large bore catheter (11 with Route 92 Medical Hipoint 88 catheter and 2 with Route 92 Medical Freeclimb 88 catheter). In all cases, successful navigation of the paired catheter through the cervical lesion was achieved in 100% of patient using the Tenzing‐Dotter delivery technique. The mean time from groin puncture to successful Tenzing‐Dotter delivery was 11 minutes, and the mean time from groin puncture to device delivery to the intracranial occlusion was 15 minutes. TICI 2B or greater reperfusion (self‐adjudicated) as achieved in 100% of patients, with a mean time to best TICI of 21 minutes. The degree of cervical ICA stenosis following thrombectomy improved from 96.5% to 67.4%. No symptomatic intracranial hemorrhage or cervical arterial dissections were noted.

Conclusion
The Tenzing‐Dotter technique, in which a Route 92 Medical Tenzing ® delivery catheter is utilized to Dotter navigate a large or super‐large bore catheter through an occluded or nearly‐occluded cervical atherosclertotic lesion, may be a promising technique for safe and fast access to the intracranial circulation in patients presenting with tandem large vessel occlusion acute ischemic strokes.