1. Expanding Time Windows Present Niche Endovascular Stroke Care Opportunities
Faheem Sheriff , Joshua Hirsch, Christopher Stapleton, Matthew Koch, Susan Williams, James Rabinov, Aman Patel, Thabele Leslie-Mazwi
Massachusetts General Hospital Boston MA Harvard Medical School Boston MA
INTRODUCTION
CASE 1:
History:
53 y/o M with PMH of cardiomyopathy due to Becker’s muscular dystrophy who underwent LVAD placement and TV repair; as sedation was being lifted he was noted to have developed Rt MCA syndrome with NIHSS 20. (7.25 hours post cannulation; LSW to detection 12 hrs)
Imaging:
CT head with ASPECTs 9; CTA and angio with proximal Rt M1 cutoff(Figure 1B). Time from LSW to groin puncture was 16 hours and 20 minutes. TICI 2b recanalization attained at 1 hours 57 minutes (1C and D). Clot pathology was consistent with unorganized thrombus. 24 hour CT head showed minor contrast blush and hypodensities in caudate head / lentiform nucleus (1E) . MRI at 6 months showed FLAIR changes in basal ganglia with cortical sparing.
CASE 5:
History:
70 y/o M admitted for A-fib with RVR and severe MR who underwent mitral valve replacement and MAZE procedure. Post procedure he was neurologically intact; Rt MCA syndrome developed ( NIHSS 7) at 15 hours 30 min post onset of procedure (LSW to detection 2.5 hours).
Imaging:
CT head showed early ischemic changes with hypodensity in M1 (Fig 2A); CTA showed Rt M1 occlusion. (Fig 2B). Time from LSW to groin puncture was 4 hours 35 minutes. During IA (Fig 2C), the embolus was easily traversed but partial recanalization was achieved (TICI 2a). Pathology of embolus revealed mature adipose tissue (Figure 2D). Day 3 head CT showing significant infarct burden. (Figure 2E). Procedure complicated by small ICA dissection.
RESULTS (cont…):
Median procedure duration was 56 minutes. Only 2/5 patients achieved mTICI scores of ≥2b.
Clot pathology was obtained in 2 cases and showed mature adipose tissue (mTICI 2a, see case 5 ) and un-organized thrombus (mTICI 2b, see case 1).
Hemorrhagic conversion occurred in 3/5 patients (one PH2). NIHSS at day seven ranged from 0-21 (median 7).
The DAWN and DEFUSE 3 trials have major implications for strokes caused by large vessel occlusion (LVO) that present outside of conventional treatment windows. We present our post-DAWN experience with a unique subpopulation, patients undergoing cardiothoracic surgery.
METHODS
A prospective institutional stroke database was reviewed between May and August 2017 for cardiothoracic patients with LVO.
CONCLUSION:
Endovascular stroke therapy for patients post cardiothoracic surgery is characterized by late treatment windows and sometimes  technically challenging procedures due to unusual embolic pathology (e.g muscle or lipid, not clot) [1,2]. These unusual embolic materials may not be able to interact with the thrombectomy devices as readily as thrombus.
Conventionally the patient is last seen well prior to induction of general anesthesia; however onset of embolism likely coincides with the moment of endocardial violation or in case of CABG during clamp placement / removal (as suggested by showers of microembolic signals seen by transcranial Doppler [3]).
However, these patients represent a niche that has been opened by positive late window trial data where late window thrombectomy treatment may positively modify the complication profile of cardiothoracic surgery.
RESULTS
Five cardiothoracic patients met criteria for emergent thrombectomy due to LVO. All had left heart surgical endocardial violation. At presentation, median NIHSS was 16 and ASPECTS ranged from 7 to 9.
All patients had M1 occlusions (except for one M2) . Patients fell into two categories (see Table 1) :
Detection of deficit on emergence of the sedated patient from anesthesia (LSW to diagnosis median of 750 minutes) [color coded teal], represented by case 1. These were patients placed on cardiopulmonary bypass, and warmed before being transferred to cardiac critical care for weaning of sedation.
Detection of new deficit in the alert patient 1-2 days after surgery (Last seen well (LSW) to diagnosis median of 120 minutes) [color coded gray], represented by case 5.
Table 1: A C D E B A C E B D
Table 1:
Case no. `
Age
mRS
Cardiac surgery type
NIHSS
Initial ASPECTS
24 hr CT head
LSW to Dx (min)
Time from LSW to detection
LSW to CTA (min)
Groin puncture to recanalization
Angio result (TICI)
Clot path (if available)
Device(s) used
Hemorrhagic conversion
Complications
NIHSS Day 7
mRS at last followup 1. 53 3
LVAD placement, TV repair 20 8
contrast blush in caudate head and lentiform nucleus
720
12 hours
937
1 hr 57 min 2b
Unorganized thrombus
Solitaire X3 No
None 9 2. 37 1
Aortic valve replacement and arch repair for aneurysm 24 7
contrast blush vs hemorrhage; early cerebral edema
780
13 hours
950
16 min
unavailable
Clot suction x1
Yes (PH2)
Malignanct cerebral edema; hemicrani 21 4 3. 67
Elective TAVR (OSH) 16
Subarachnoid hemorrhage 15
15 min 77
43 min 2a
ADAPT X2 Solumbra X2
Yes (SAH)
SAH 4.
Prior BiVAD placement
contrast blush
120
2 hours
139
56 min
Solumbra X 2
none 6 5. 70
MVR, MAZE procedure
Minor hemorrhagic conversion, evolution of hypodensity
150
2 hours 30 min
207
1 hour 21 min
Mature adipose tissue
Solumbra X 3
Yes (HI1)
Small ICA dissection 5 2
Figure 1: A: Scout showing pacemaker, ETT, sternal wires and post-op monitors. Patients are complex travels and usually cannot get MRI. B: CTA with Rt M1 cutoff and reasonable collaterals. C: Initial angiogram with proximal Rt MI cutoff. D: Full recanalization after 3 passes. E: Day 2 head CT showing final stroke volume.
Figure 2: A: Initial head CT showing hypodensity in distal Rt M1. B: Corresponding vessel occlusion on CTA. C: Angiographic appearance of Rt M1 filling defect. Only a mTICI 2a result was achieved after both aspiration and stentriever attempts. D: Pathology on embolic fragments showing mature adipose tissue. E: Day 3 head CT showing significant infarct burden.
Outcome:
NIHSS at one week was 9. Discharged to rehab and eventually home. mRS at three months was 3 i.e baseline functioning prior to stroke. Could ambulate 100 feet before tiring but dependent on wheelchair for long distances.
Outcome:
NIHSS at one week was 5. Started on therapeutic anticoagulation. Discharged to rehab and eventually home. mRS at two months was 2. Repeat CTA showed no pseudoaneursym.
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Avila JD. Hypodense artery sign in cerebral fat embolism. Practical Neurology 2017;17:
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