====== Tandem occlusion ======

A [[tandem]] [[occlusion]] is an uncommon presentation of [[acute ischemic stroke]] that involves occlusion of the extracranial [[internal carotid artery]] (EICA) and concomitant occlusion of either the [[intracranial]] [[internal carotid artery]] and/or [[middle cerebral artery]].


Tandem lesions (e.g. carotid siphon and bifurcation stenosis): although this topic remains controversial, [[CEA]] in patients with [[tandem occlusion]]s has not been associated with increased postoperative stroke rates.
((Faries PL, Chaer RA, Patel S, et al. Current manage- ment of extracranial carotid artery disease. Vasc Endovascular Surg. 2006; 40:165–175))
((Rouleau PA, Huston J,3rd, Gilbertson J, et al. Carotid artery tandem lesions: frequency of angio- graphic detection and consequences for endarter- ectomy. AJNR Am J Neuroradiol. 1999; 20: 621–625)).

===== Treatment =====

[[Tandem occlusion treatment]].

===== Case series =====
Limaye  et al. analyzed a [[retrospective]] [[database]] of [[Carotid artery stenting]] (CAS) patients from the University of [[Iowa]] Hospitals and Clinics. They included patients with symptomatic isolated ipsilateral [[extracranial carotid artery stenosis]] and acute [[tandem occlusion]]s who underwent CAS. Hyperacute CAS (HCAS) and acute CAS (ACAS) groups were defined as CAS within 48 hours and >48 hours to 14 days from symptoms onset, respectively. The primary outcome was a composite of any [[stroke]], [[myocardial infarction]], or [[death]] at 3 months of follow-up. Secondary outcomes were periprocedural complications and restenosis or occlusion rates.

They included 97 patients, 39 with HCAS and 58 with ACAS. There was no significant difference between groups for the primary outcome (HCAS 3.3% vs. ACAS 6.1%; p = 1). There were no differences in the rate of perioperative complications between groups although a trend was observed (HCAS 15.3% vs. ACAS 3.4%; p = .057). The rate of restenosis or occlusion between groups (HCAS 8.1% vs. ACAS 9,1%; log-rank test p = .8) was similar with a median time of follow-up of 13.7 months.

Based on this study, CAS may be feasible in the hyperacute period. However, there are potential higher rates of perioperative complications in the hyperacute group, primarily occurring in [[mechanical thrombectomy]] (MT)  patients with acute [[tandem occlusion]]. A larger [[multicenter]] study may be needed to further corroborate this findings
((Limaye K, Quispe-Orozco D, Zevallos CB, Farooqui M, Dandapat S, Mendez-Ruiz A, Ansari S, Abdelkarim S, Dajles A, Derdeyn C, Samaniego EA, Ortega-Gutierrez S. Safety and Feasibility of Symptomatic Carotid Artery Stent-Assisted Revascularization within 48 Hours after Symptoms Onset. J Stroke Cerebrovasc Dis. 2021 Mar 22;30(6):105743. doi: 10.1016/j.jstrokecerebrovasdis.2021.105743. Epub ahead of print. PMID: 33765635.)).

===== Case reports =====


A 70-year-old man was admitted to the hospital due to sudden inability to speak and inability to move his right limb for 3 h. Imaging confirmed a diagnosis of a [[tandem occlusion]] in the left carotid artery with a left [[M1]] occlusion. Carotid artery incision thrombectomy combined with stent [[thrombectomy]] was performed. The operation was successful, and 24 h later the patient was conscious and mentally competent but had motor aphasia. His bilateral limb muscle strength level was 5, and his neurologic severity scores score was 2.

Carotid artery incision thrombectomy combined with stenting for carotid artery plus cerebral artery tandem embolization is clinically feasible. For patients with a complicated aortic arch and an extremely tortuous carotid artery, carotid artery incision can be chosen to establish the interventional path
((Zhang M, Hao JH, Lin K, Cui QK, Zhang LY. Combined surgical and interventional
treatment of tandem carotid artery and middle cerebral artery embolus: A case
report. World J Clin Cases. 2020 Feb 6;8(3):630-637. doi:
10.12998/wjcc.v8.i3.630. PubMed PMID: 32110676; PubMed Central PMCID: PMC7031835.
)).