What is Dolichoectasia?
Dolichoectasia is a rare cerebrovascular disorder characterized by abnormal fusiform dilatation, elongation, and tortuosity of cerebral arteries, most commonly affecting the vertebrobasilar system. 1
Pathological Definition and Features
Dolichoectasia represents a specific form of arteriopathy with distinct pathological characteristics:
Structural abnormalities include an abnormally large external arterial diameter with a thin arterial wall, degeneration of the internal elastic lamina, multiple gaps in the internal elastica, thinning of the media secondary to reticular fiber deficiency, and smooth muscle atrophy 2
Vascular distribution preferentially involves the intracranial vertebral and basilar arteries (posterior circulation), though anterior circulation involvement can occur 2, 3
The term "fusiform" describes the shape of these dilated vessels, distinguishing them from saccular aneurysms 1
Clinical Significance and Presentations
The disorder presents through three primary mechanisms:
Acute ischemic events occur because flow in dilated arteries becomes bidirectional with reduced antegrade flow and thrombus formation; elongation and angulation can stretch and distort branch orifices, particularly affecting penetrating arteries 2
Progressive compressive symptoms result from mass effect on cranial nerves, the brain stem, or the third ventricle (causing hydrocephalus) 2, 3
Catastrophic hemorrhagic complications from vascular rupture, though less common 2
Associated Risk Factors
Dolichoectasia shares epidemiological associations with traditional vascular disease:
Age-related prevalence increases with advancing age 4
Traditional cardiovascular risk factors including hypertension and male sex are strongly associated 1
The relationship to atherosclerotic disease remains unclear, though both conditions may coexist 1
Diagnostic Considerations
Visual assessment of vessel shape is required for diagnosis:
Smoker's criteria should be applied when the posterior circulation is affected 4
Reproducible diagnostic criteria for anterior circulation dolichoectasia are lacking, making diagnosis more challenging in these cases 4, 5
Imaging should document vessel diameter, degree of tortuosity, and presence of associated complications like thrombus or mass effect 1
Management Approach
For patients with vertebrobasilar dolichoectasia and a history of ischemic stroke or TIA without other attributable causes, either antiplatelet or anticoagulant therapy is reasonable for preventing recurrent ischemic events. 1, 6
No specific treatment exists to arrest or reverse the arterial dilatation process itself 4, 7
Antithrombotic therapy addresses the thromboembolic risk from flow stagnation 1, 6
Blood pressure control and cardiovascular risk factor management are essential components of care 6
Critical Pitfalls
Do not assume anticoagulation is superior to antiplatelet therapy despite theoretical concerns about flow stagnation—evidence does not support routine anticoagulation over antiplatelet agents 6
Progressive arterial enlargement predicts mortality, but no proven interventions slow this progression 7
The disorder can involve both anterior and posterior circulations simultaneously, which is extremely rare but must be recognized 3