Infarct in new territory after endovascular stroke treatment: A diffusion-weighted imaging study

Abstract

Data on infarcts in new territory (INT) in patients undergoing endovascular stroke treatment for acute large-vessel occlusions are sparse. Aim of this study was to assess the prevalence, risk factors, and clinical relevance of INT. For this purpose, all patients in a single-center prospective registry who underwent endovascular stroke treatment and received pre- and post-interventional diffusion-weighted imaging were included (N = 259). Using an established scoring system, INT were classified according to size (I-III, ≤2 mm, >2 mm ≤20 mm, >20 mm) and likelihood of being related to the intervention (A, high likelihood; B, low likelihood). Additionally, a new type of infarct, that occurred in a territory distal to the occlusion, but was initially not hypoperfused, was defined as an infarct in initially not hypoperfused territory (IINHT). A total of 180 INT and 38 IINHT were observed in 32.8% (N = 85/259) of patients. In most patients, INT were angiographically occult (90.2%), and 13 patients had INT/IINHT larger than 2 cm (type III). Absence of protection during stent-retrieval and a cardio-embolic stroke origin were associated with higher incidence of INT/IINHT, whereas pretreatment with IV tPA showed no association, even when different bolus timing was considered. INT/IINHT were associated with lower rates of functional independence with increasing size type after adjusting for confounders (adjusted Odds Ratio per size group increase 0.63, 95% confidence interval 0.46–0.86). In conclusion, INT and IINHT are not rare, are associated with poor outcome with increasing size, and they may serve as a surrogate endpoint for safety evaluation of new devices and endovascular techniques. Further research on associated factors is warranted.

Evaluation of time-resolved whole brain flat panel detector perfusion imaging using RAPID ANGIO in patients with acute stroke: comparison with CT perfusion imaging

“…The use of FD-CTP post-thrombectomy is another possible application and the next frontier where FD-CTP could add significant value. In cases of incomplete thrombectomy with residual occlusion—for example, the decision whether to perform rescue maneuvers (eg, with distal stent retrievers24 25 or administration of a thrombolytic drug26 27) or to stop, is currently open to discussion. Intraprocedural magnetic resonance may also aid in such real-time treatment decision-making,28 although FD-CT is considerably simpler from a workflow standpoint.…”

Impact of intravenous alteplase on sub-angiographic emboli in high-resolution diffusion-weighted imaging following successful thrombectomy

“…Further research could investigate whether PE have an effect on NIHSS scores stratified by symptoms, or with further neurological assessment scores that represent more subtle cognitive changes. Accordingly, Kaesmacher et al showed recently that infarcts larger than 2 cm distal to the occlusion in initially not the hypoperfused territory and new territories are associated with poor outcome [22]. Further studies are warranted to investigate the impact of interventional techniques and devices with regard to thrombus characteristics on the occurrence of PE after MT and their influence on outcome [16,23].…”

Transcirculation Embolization to New Territory During Mechanical Thrombectomy for Acute Ischemic Stroke

“…In a separate study, pretreatment with intravenous thrombolysis again failed to show an association with rate of INT. 3 At this time, the association of pretreatment intravenous thrombolysis prior to mechanical thrombectomy and rates of ENT remains unclear.…”

“…3 Large INT (>20 mm) has been shown to be relatively rare with a rate of 5%. 3 The rate of ENT is dependent on a variety of factors including choice of endovascular device, 4 incorporation of balloon guided catheters, 5,6 and method of procedural sedation. 7 Trans-circulation ENT is a rare entity and optimal management is unknown.…”

“…2 Most INT (35%) have been shown to be small (<2 mm) and not related to catheter manipulation across the new infarct territory ostium. 3 Large INT (>20 mm) has been shown to be relatively rare with a rate of 5%. 3 The rate of ENT is dependent on a variety of factors including choice of endovascular device, 4 incorporation of balloon guided catheters, 5,6 and method of procedural sedation.…”