23 Superior Vena Cava Syndrome

5. Classification of SVCS 

Several classifications of SVCS have been proposed even though further investigations are 

required to achieve a definitive staging system. There are three main classification proposals 

which follow different methods of categorization [18-20]. 

1.     Doty and Standford’s classification (anatomical) 

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Type I: stenosis of up to 90% of the supra-azygos SVC 

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Type II: stenosis of more than 90% of the supra-azygos SVC 

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Type III: complete occlusion of SVC with azygos reverse blood flow 

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Type IV: complete occlusion of SVC with the involvement of the major tributaries 

and azygos vein 

2.    Yu’s classification (clinical) 

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Grade 0: asymptomatic (imaging evidence of SVC obstruction) 

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Grade 1: mild (plethora, cyanosis, head and neck edema) 

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Grade 2: moderate (grade 1 evidence + functional impairment) 

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Grade 3: severe (mild/moderate cerebral or laryngeal edema, limited cardiac 

reserve)   

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Grade 4: life-threatening (significant cerebral or laryngeal edema, cardiac failure)  

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Grade 5: fatal  

3.    Bigsby’s classification (operative risk) 

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Low risk  

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High risk 

The authors proposed an algorithm for SVCS to assess the operative risk in order to submit 

the patient to invasive diagnostic procedures. The low risk patients present: no dyspnea at 

rest, no facial cyanosis in the upright position, no change of dyspnea and no worsening of 

facial edema and cyanosis, during the supine position. The high risk patients present facial 

cyanosis or dyspnea at rest in the sitting position.